My Little Sister Is the Best F*p Material - Volume 5 Chapter 4: Heartbreak Letter and the Final Training

Volume 5 Chapter 4: Heartbreak Letter and the Final Training

The low hum of the air conditioner filled the quiet bus as I gazed out the window, watching the unfamiliar scenery pass by. Just hours ago, when I first boarded the bus, I was filled with anxiety and urgency. Now, a sense of calm settled over me, as if I’d stepped into another world. I’ve made up my mind—I’ll make Miyu happy. I’m certain of it. So, I don’t think I’ll have much to discuss with Yamamoto-san.

But I do want to thank her. There’s no doubt that Yamamoto-san helped me regain my confidence. Knowing how much she’s supported me, I’m sure she’ll be happy to hear that Miyu and I are together.

Or so I thought.

“Sorry to say this after asking for advice, but the issue’s resolved. My worries are gone for now.”

I sent Yamamoto-san that message and waited for her reply. The reason was simple: I wasn’t sure what the honest thing to do was.

Yamamoto-san supported my relationship with Miyu. I don’t doubt her sincerity, but now I also believe her words about being “a little bitter” were genuine.

So, if her reply is something like, “Congratulations! Be happy!”—meaning she’s figured everything out—I’ll head home. I do want to thank her and ask what she liked about me, but if it’s just my ego, I’ll let my curiosity go.

“Your worries are resolved? That’s great. I’m free, but what about you? Want to come over?”

Yamamoto-san’s message unexpectedly passed the baton to me. But thinking about it, it makes sense. I initiated this, so it’s up to me to decide.

Her message seems like an invitation. If she didn’t want me to come, she wouldn’t have asked. Maybe she’s looking forward to seeing me.

She might’ve sent her brothers home early just for me. I wouldn’t want to cancel plans after inviting her. I feel bad about backing out now.

“Not sure. Maybe grab a quick bite nearby?”

When I asked for advice, I was desperate to make Miyu happy, so I didn’t consider Yamamoto-san’s schedule. But now that my worries are gone, it’d just be me bragging about my happiness. She wouldn’t attack me out of jealousy, but I don’t want to make her uncomfortable.

So, I suggested eating instead of just talking. This way, even if the conversation doesn’t go towards Miyu, we won’t have an awkward time.

“I already showered, so going out is a bit… If you’re free, come over! I have something to talk about too!”

Another unexpected reply. If she has something to say, there’s no reason not to go. Well, except for what Yuka said about visiting another girl’s house while having a girlfriend.

I do have something to ask Yamamoto-san: about Miyu’s comment regarding Yuka and her. Miyu seemed to know I’d visit Yamamoto-san. Maybe Yamamoto-san knows everything and is waiting for me?

“Maybe I’m overthinking,” I muttered. Just then, another message from Yamamoto-san arrived.

“Miyu told me everything, so come over.”

My spine chilled. So, they knew all along.

“I’ll be there soon. I’ll text you when I reach the apartment.”

What will we talk about? I can’t imagine it ending cheerfully with, “I’m with Miyu now!” “I knew it! Congratulations!”

But Yamamoto-san wouldn’t be unhappy for me. I’ll stay confident.

I arrived at her apartment, and she unlocked the entrance. Standing before her door, it felt strangely impersonal.

She opened the door before I could ring the bell.

“Welcome, Sotomichi-kun.”

The cool air inside carried a faint citrus scent. Fresh from her shower, Yamamoto-san wore just a T-shirt, her hair and clothes clean. I was sweaty from walking outside, hesitant to enter.

“Here you go.”

As if reading my mind, she opened the bathroom door. Inside were folded towels, the T-shirt I’d used on my first visit, and my trunks, probably left in the washing machine.

It was efficient, but it reassured me. During our time together, we’d established an unspoken rule: “If there are clothes ready after a shower, no intimacy.” Given who she is, I took this as her subtle consideration.

“Thanks. I’ll be quick.”

“Take your time. I’m just lounging.”

I showered, hesitating for a moment before using the shampoo. I washed thoroughly from head to toe, then changed and dried my hair. The summer humidity and my worries seemed to wash away, leaving me refreshed.

“I’m done.”

In the living room, Yamamoto-san was lying on the bed, scrolling through her phone. Her relaxed, sideways posture reminded me of Miyu, and I thought how inconvenient large-chested girls must find it.

“Want to join me?”

She teased, spreading her arms in invitation.

“Thanks, but I’ll pass for now.”

I sat on the carpet, using the edge of the bed as a backrest. I figured this response would be fine since I’d already heard the story from Miyu.

“You’re looking good again these past few days.”

Yamamoto-san sat up and perched on the edge of the bed, gently patting my head. Then she sat down next to me, and we sat side by side. Close enough that our arms would brush if we moved, but not so close that we could feel each other’s body heat. That distance seemed to sum up our current relationship.

“It’s all thanks to you, Yamamoto-san.”

The fact that I’d gotten together with Miyu, and that I’d regained my confidence—both were things that had happened because Yamamoto-san had encouraged me in this very room.

“Thanks. I really mean it, from the bottom of my heart.”

Before, I’d been so hopeless and distrustful of women, but now, without even realizing it, I was surrounded by lots of girls, getting asked for dating advice, and even getting invited to… well, you know. Miyu was the one who’d shaped the core of who I am, but it was Yamamoto-san’s words that had given me the push I needed to regain my confidence.

“Is that so? Then, can I ask for a token of your gratitude?”

Yamamoto-san hugged her knees, giving me that mischievous smile again. Why are you girls so straightforward?

“I’d like to give you something appropriate, of course. Is there anything you want?”

She probably wouldn’t ask me to buy her something as a reward. And a memento doesn’t seem likely either. I can’t think of anything I have that Yamamoto-san would want.

“Well… this.”

Yamamoto-san’s gaze fell to my arm. Surely she doesn’t mean my actual arm, right? Given the situation, I guess she’s asking for a hug or something.

“Uh… is it my arm you want?”

When I asked, Yamamoto-san shook her head. It didn’t seem like she was asking for a hug, which was a relief. Getting that close to Yamamoto-san would be a bit much for me to handle rationally.

I’d never thought I’d live a life where girls would be into me, so I don’t know how to turn down these kinds of advances or requests. If she were like Yuka and just acted selfishly, it’d be easier to refuse, but rejecting her request in this somber atmosphere feels especially awkward.

“If… if I could close this gap between us, I’d be really happy.”

Yamamoto-san looked sadly at the space between us. Basically, she doesn’t like feeling avoided and wants to get closer. But how should I take this?

If it’s just our arms touching, that’s fine, I guess. After all, I’m already all over Sachiko. If this is a lighter request than that, it’s not like I can flat-out refuse. Yamamoto-san just doesn’t want me to suddenly go cold on her, right?

“If it’s just that, then sure.”

When I gave her permission, Yamamoto-san exhaled like a weight had been lifted and closed the distance between us by a few centimeters. Maybe because the air conditioning was a bit strong, Yamamoto-san’s body heat felt especially intense. The faint sensation of our skin touching felt vivid.

“It’s a bit cold.”

I needed a moment to calm my heart, so I muttered that, intending to ask her to grab the remote. But Yamamoto-san didn’t move a muscle, just stayed pressed against me, staring intently.

“Yeah, it is cold.”

Yamamoto-san’s eyes glistened, and the warmth from her arm grew more intense. My heart started racing, and the air between us thickened.

“Yamamoto-san, um…”

When I tried to create some space again, Yamamoto-san gently placed her right hand over my left, our fingers intertwining. The gap between us narrowed, inch by inch, almost to nothing.

I reflexively pulled my hand away, but Yamamoto-san held on tight. And when I instinctively leaned back, she seized the moment to push me down.

“Whoa, wait! Yamamoto-san, that’s…!”

Yamamoto-san pinned me down with her full weight, stopping me from getting up.

“You said it was okay to close the gap, right?”

Her fresh body pressed against mine, she whispered sweetly in my ear. Caught off guard by Yamamoto-san’s sudden boldness, I tried to push her off with all my strength, but she wouldn’t budge.

“This is really bad! I’m with Miyu now…! And you knew that, right, Yamamoto-san?! Let’s just… calm down. I don’t dislike you, so let’s talk this through for both our sakes…!”

As I desperately tried to reason with her, Yamamoto-san wrapped her arm around my neck, her shoulders trembling. Despite my shock, my priority was still Miyu. I gently tapped Yamamoto-san’s back, trying to get her to let go.

Yamamoto-san’s diaphragm was still quivering, and soon a small laugh escaped her.

“Y… Yamamoto-san…?”

Confused, I watched as Yamamoto-san lifted her head, her hand over her mouth. Her expression, too joyful to be fully hidden, showed she was struggling to contain her laughter.

“You… your reaction is so different from before, Sotomichi-kun.”

Yamamoto-san’s voice finally regained its usual liveliness. Then, with a light movement, she got off me, pulled me up by the hand, and helped me sit up.

“Don’t do that… my heart can’t take it.”

It seemed like it was all just Yamamoto-san’s prank. My heart was racing, and my vision was going white.

“So you and Miyu-chan are really a couple now… I see.”

Yamamoto-san said it with a sense of wonder. Apparently, the prank was to test whether what Miyu had said was true.

“It still doesn’t feel real to me either. When did Miyu contact you?”

Since Yamamoto-san had heard everything from Miyu, they must have talked while I was out for those few hours. Even Yamamoto-san couldn’t have predicted the exact timing of me and Miyu getting together.

“Hmm? What do you mean?”

But Yamamoto-san tilted her head, her finger on her lips.

“Miyu told you about me, right?”

When I’d frantically tried to push Yamamoto-san away, she’d seemed to understand my reaction, so Miyu must have told her something in advance.

Only Yamamoto-san could notice this discrepancy in our understanding.

“Ah… yes, she did. Miyu-chan told me.”

Yamamoto-san grinned, crawling closer on all fours. Just like before, she poked my chest with her finger and slowly moved her lips.

“While you were at your part-time job.”

The unexpected answer from Yamamoto-san. Miyu and Yamamoto-san had met and talked in person three days ago—while I was at the part-time job I’d gotten the date wrong for.

“We talked about everything. Like what kind of conversations you and I had, and what kind of… intimate things we did. Even things I haven’t told you yet, girl talk.”

Yamamoto-san’s voice had a strangely sultry tone, making it clear that their conversation hadn’t been as lighthearted as tea on a terrace.

What kind of girl talk could Miyu and Yamamoto-san have had that I didn’t know about? Was Miyu’s side of the story the same as what she’d told me over the past two days? If so, what was this “girl talk” Yamamoto-san hadn’t shared yet? It was intriguing.

“So, during that talk, you knew Miyu and I would end up together. You figured out it was today from my message, right?”

“Yep. You’re catching on quickly, Sotomichi-kun.”

There was no way I’d turn down Miyu’s confession. So, once Miyu told Yamamoto-san she liked me, Yamamoto-san must have known this day would come.

“Miyu never mentioned meeting you. Was it her idea to meet three days ago?”

“Yeah. She straight-up declared, ‘He’s mine.'”

That was… unexpected. Was I supposed to know this behind-the-scenes story?

“Was it because of that phone call?”

“Hmm… in a way, maybe…”

Yamamoto-san hesitated, nodding vaguely. It seemed like that wasn’t entirely the reason.

“Is it okay to ask what exactly you talked about?”

“It’s not a problem, but… I’d rather not get into specifics…”

Yamamoto-san turned her face away, her cheeks reddening.

“I was grilled in this very room…”

“Oh… I see.”

She must have gotten a stern lecture on the bed. Miyu wouldn’t hold back, and she might have even made Yamamoto-san reenact things. I decided not to think too deeply about it.

“We also talked about your past and stuff. Miyu said you’re a good cook, too.”

“Compared to you, Yamamoto-san, it’s nothing special, but I have some experience.”

“I see. Then, how about you make dinner for us tonight?”

It was just past six in the evening. Cooking for Yamamoto-san wouldn’t be a problem. And it would make up for the earlier awkwardness.

“Sure. What would you like?”

“Omurice!”

“Got it.”

I immediately agreed, but omurice was a tricky dish. I hoped I could roll the egg properly with a different type of pan.

The fridge was well-stocked, as expected. But there was no chicken. Why choose omurice without chicken? The main ingredients were eggs, pork, and assorted vegetables. No milk, so no cream sauce.

“How about omurice with pork stew?”

“Sounds great! As long as it looks like omurice, I’m happy.”

It was a subtle compromise, but I’d make it work. I’d just cook it the way I always did.

As I started cooking, Yamamoto-san stood behind me, hands clasped, watching with a smile. I was used to Miyu’s guidance, so I wasn’t too nervous, but I’d eaten Yamamoto-san’s cooking many times and knew how skilled she was. The pressure was definitely on.

I finely chopped the onions, mixed the sauces and seasonings, added the pork and other ingredients, and let it simmer on low heat. Meanwhile, I fried the rice, seasoned it, rolled it in an egg, and plated it. Then I poured the stew over it. Only after did I realize I should have made a thin omelette or placed the stew on top of a cut egg—it looked messy.

Normally, I’d add some green garnish, but basil didn’t seem right here. Instead, I reduced a balsamic sauce to a darker color than the stew and drizzled it over like ketchup. It was a bit over the top, but it would do.

I cleaned the dishes in order, starting with those that could handle temperature changes. I soaked the dirty sponges in detergent.

“Here you go.”

I showed Yamamoto-san the plate, and she took it, inhaling deeply.

“Mmm! It smells amazing! Thank you, Sotomichi-kun. It’s so full of love, I’m satisfied already. Go ahead and leave the dishes; come sit with me.”

Yamamoto-san gestured for me to join her at the table, and I sat beside her without hesitation.

She happily broke the egg with her spoon and took a big bite. Yamamoto-san seemed different somehow—more like a girl her age.

“This is so good! I’m surprised. I should’ve asked you to cook during your stay last week.”

“I did offer to help.”

“Right… my mistake…”

Yamamoto-san looked dejected but kept eating quickly. She seemed to like it.

It had been a while since I’d cooked for anyone besides Miyu. Seeing her enjoy it so much made it all worthwhile.

“Sotomichi-kun, you only tasted the stew, right?”

“Yeah. How’s the egg?”

“You should try it yourself.”

Yamamoto-san scooped up some omurice and brought the spoon close to my lips. I opened my mouth and took a bite. Despite the unfamiliar pan, the egg was evenly cooked.

“Hehe. You ate it, Sotomichi-kun?”

“Huh? Oh, yeah. I did, but…”

Yamamoto-san gave a creepy smile and scooped up another bite.

“Here, open wide.”

This time, she carefully held my free hand and brought the spoon to my mouth.

“Uh, I don’t think—”

“You did it earlier, too.”

“Well, that was… different…”

“Just open your mouth. Please eat it.”

She pushed the spoon toward me, and I took another bite. Yamamoto-san watched with amusement. What was she up to? Was this her way of getting back at Miyu for the lecture? If so… it made sense.

“That was delicious. Thanks for the meal, Sotomichi-kun.”

“You’re welcome.”

After Yamamoto-san finished eating, a brief silence fell between us.

“Hey, Sotomichi-kun,” Yamamoto-san murmured, staring at the wall.

“Next time, I’d like us to cook together.”

Her casual words, a common wish, seemed to fade into the void. I couldn’t even manage a simple acknowledgment. All I had to do was say, “Yeah,” but I couldn’t.

“Just kidding. I’ll go wash the dishes.”

Yamamoto-san bounced up and headed to the sink. 

I didn’t dwell on the meaning of our exchange. My mind was flooded with suspicions, so I focused on staying calm. I leaned back on the bed, exhausted.

Then, I heard a faint rustling sound, like paper rubbing against something. I thought I’d stepped on one of Yamamoto-san’s documents and quickly moved away. But there was no paper nearby. When I leaned back on the bed again, the rustling sound returned.

After pressing the mattress a few times, I realized there was something between the frame and the mattress. I slipped my finger in and felt a slight thickness. Pulling it out, I found a Western-style envelope, postcard-sized, sealed with a heart-shaped sticker. It was, without a doubt, a love letter.

“Sotomichi-kun?”

Startled by Yamamoto-san’s voice from behind, I instinctively hid the envelope behind me. She’d finished the dishes and was back in the room, looking confused at my strange behavior.

“Uh… I didn’t mean to…!”

There was no point in hiding it so obviously. I confessed to finding the envelope.

“……You found it, huh.”

Yamamoto-san was surprisingly calm. She took the envelope from me with two fingers. It was clearly a love letter. Why had she hidden it there?

I wasn’t sure how much to say. Ignoring it would probably be best, but that would leave us both feeling uneasy.

“Is that… a love letter?”

I asked, hoping that even if her answer was a lie, we’d at least be on the same page.

“Hmm… well…”

Yamamoto-san tucked her hair behind her ear and gave a wry smile.

“More like a rejection letter, I guess.”

She said it with self-deprecation, a sad term.

It was a love letter written with the expectation of rejection. Given the situation, it seemed like Yamamoto-san had written it to me after I’d gotten together with Miyu. It was an arrogant assumption, but considering the time we’d spent together today, it felt inescapable.

What was I supposed to do with something like that? I couldn’t deny Yamamoto-san’s feelings, but pretending the letter didn’t exist and hearing her feelings directly might be easier to process.

“You wrote this after I came to your room, right…?”

At least, when we were intimate, the envelope wasn’t there. Yamamoto-san had developed feelings for me during the week we spent together, but since I was with Miyu, she couldn’t give it to me… or something like that.

“Well, you’d think so, right?”

Her response was unexpected.

“If I’m being mischievous, I received this letter.”

Yamamoto-san fluttered the envelope and placed it on the table like a discarded toy.

“Oh… I see.”

It was a complete misunderstanding. Embarrassingly wrong, but the essence of the situation hadn’t changed.

Yamamoto-san called the letter she received a “rejection letter.” It meant someone was destined to lose in love. Logically, the one rejected would be the man who gave Yamamoto-san the letter.

But if that were the case, Yamamoto-san’s distress didn’t make sense. She’d received countless love letters before; why would rejecting someone trouble her now? The fact that she kept this letter meant it held special significance.

Yamamoto-san hadn’t immediately disposed of the letter. That meant she was considering the man’s offer. Why was she hesitating? That was why she called it a “rejection letter.”

“Yamamoto-san,” I said, steeling myself. There’s no such thing as a choice that makes everyone happy or a life that hurts no one. Such naivety only leads to more pain.

“Hmm? What is it?”

Yamamoto-san’s expression still held a playful glint, as if she hadn’t fully accepted my choice yet.

“I—”

My voice trembled.

My throat felt constricted, but I had to say it.

“I’ve decided Miyu is my top priority, and I want to be happy with her. So I can’t choose anyone else.”

No matter how comfortable being with Yamamoto-san felt.

People have a limited number of places they can call home.

“Oh… right.”

Yamamoto-san’s breath caught, and her eyes darted around.

My answer must have been unexpected. Or perhaps she’d known but pushed the thought away.

Then she smiled brightly.

“Of course. You and Miyu-chan are in love now. You should give her all your affection.”

She forced a smile, her eyes curving into arcs, but it faltered slightly.

I’d never seen such a heartbreaking smile.

Then, the tension in Yamamoto-san’s body relaxed, and she rested her head on my shoulder.

“Sorry. That hit harder than I thought.”

It was the first time I heard her voice break. I almost said, “Sorry,” too, but I held back. I couldn’t deny my choice to be with Miyu.

“I’m sorry for making you feel this way. I’ll make it right somewhere down the line.”

Apologizing was just another way of running away. So I had to make this cruel choice, even if it stained my soul.

“No… it’s okay.”

Yamamoto-san pulled away, her composure returning.

“You and Miyu-chan love each other. I’d just be in the way.”

Yamamoto-san’s self-deprecating words tightened my chest even further. The weight of her guilt, making such a positive and kind person belittle herself. The more I thought about it, the more suffocating my own cruelty felt.

“N-no, that’s not what I meant! I didn’t mean to sound sarcastic or anything!” Yamamoto-san grabbed my shoulders, panicking.

“I really was cheering for you and Miyu. I’m happy things worked out, I truly am.”

Her tone grew stronger, but her voice gradually cracked.

“I should be happy for you… I should be supporting you. But… it hurts… I mean… no, that’s not what I wanted to say…”

Yamamoto-san was completely distraught, pulling me up by my arm.

“I-I’m sorry! This is my first time feeling like this, and I can’t handle it. Can we call it a day?”

“Yeah, sure. I’ll head out.”

I had so much I wanted to say, so many words of comfort I wanted to offer. But they all felt selfish. If I truly cared about Yamamoto-san, the only choice was to leave quietly.

I changed back into my clothes and hurried toward the door. As I put on my shoes, Yamamoto-san rushed out of her room.

“Sotomichi-kun, once I’ve calmed down, can we talk again? I can’t bear for things to end like this. I promise I won’t be petty anymore. Please.”

I never thought she was being petty. Her words revealed that today’s conversation stemmed from those emotions.

“I don’t want things to be awkward between us either. Let me know whenever you’re ready.”

No matter what, I wanted to remain friends. It was partly my selfishness, but I believed it was also Yamamoto-san’s wish.

“So, soon then.”

“Yeah. Thank you.”

I opened the door and stepped outside. Turning back, I saw Yamamoto-san looking slightly relieved, which comforted me too.

The sky still held a hint of light, but it would soon turn pitch black. I had to be home by 8 PM to tell Miyu I was ready to make her happy.

But my feet felt like lead. Could I convince Miyu of my sincerity in this state? Even if there was no lie, I lacked confidence.

“Ugh… this is hard…”

Before I knew it, I was sitting on a swing in a nearby park, just like a laid-off salaryman in a drama. Being in this situation, I understood the desire to just sway mindlessly.

The scent of dinner wafted from the residential area, and occasionally, I heard families chatting with their children. The park was empty. No one passed by on the street.

I wanted to confide my pain to Miyu, but tonight, I couldn’t. I’d left home seeking clues to make her happy. I had to hide my hurting heart, seeking comfort.

Even though Miyu knew my flaws, I had to act strong tonight. Sometimes, such meaningless effort was necessary, Miyu would say.

Still, I couldn’t talk about Yamamoto-san with my high school friends. Sachiko would likely encourage me kindly, but calling her this late would be an inconvenience. Through a process of elimination, I found myself messaging Yuka. Even though it was late, Yuka gave me a strange sense of reassurance in times like this.

“Are you free?” I sent a brief message. Seconds later, Yuka called me directly.

I answered with a tap.

“I’m not free!” she snapped.

“Oh, sorry. Were you busy?”

“You have the worst timing. What do you want?”

“If you’re busy, it’s fine…”

“Just spit it out!”

Was she free or not? But talking to her really cleared my head.

“It’s nothing specific. I’m just feeling down and wanted to hear your voice.”

“Huh? What? Wait, I’m putting on pants.”

I heard fabric rustling over the phone. Then static filled my earphones as she lay down on her bed.

“So, what was that about? It sounded like nonsense.”

“It’s not that there’s something to talk about. I’m just feeling low and wanted to hear your voice.”

“Stop acting like a clingy classmate. We just saw each other earlier.”

Yuka’s reaction was understandable. I felt bad for bothering her.

“Maybe you’ve fallen for Yuka-chan?”

“That’s not it.”

“Then what is it?!”

I heard rustling on the other end. Honestly, I’ve grown quite fond of her as a person, but I didn’t say that.

“Did you fail at something with that Yamamoto woman?”

“Not really, no.”

“Oh, good for you.”

Yeah, I guess so. I did well to resist Yamamoto-san’s advances.

“Actually, Yamamoto-san confessed to me, and I turned her down, which ended up hurting her…”

“Ah, so she developed feelings while you were confiding in her? That’s on her, isn’t it?”

“Maybe, but…”

True, Yamamoto-san had been cheering for me and Miyu, but once we became a couple, she was hurt. It’s a tough situation.

“But I could’ve handled it better. If I’d told her sooner that Miyu and I were together, I wouldn’t have hurt her so much.”

“I’ve heard enough of this. Everyone sleeps it off and feels better the next day. Yuka-chan knows this. If you want to wallow, do it tomorrow.”

“Yeah… maybe you’re right.”

If I keep dwelling on it, I’ll lose responsibility for my actions toward Yamamoto-san. Time to shift my mindset.

“Thanks. I feel better.”

“Good.”

Yuka abruptly changed the subject, showing no interest in my troubles.

“Unlike earlier, this time you came to me for advice, right?”

“Yeah, I guess.”

I already knew what she was getting at. But her point was valid.

“Miyu repays her debts, but what about you?”

It was a harsher question than I expected.

“Of course, I’ll show my gratitude.”

Within my means. Before I could finish, Yuka said, “Got it. I’m counting on you,” and hung up. It felt almost gangster-like, but I should repay her somehow.

“Time to go home.”

It was almost the deadline Miyu had set. It had been just one day, but it felt incredibly dense.

By the time I stood in front of our door, my mood had mostly lifted.

“I’m home.”

Miyu was waiting at the door.

“Welcome back, Onii-chan.”

Her long, well-maintained hair, flawless demeanor, and bold, confident eyes contrasted with her dangerously ample chest. Sometimes gentle, sometimes strict, yet always considerate of others. Miyu is everything to me.

“Thanks for waiting.”

I closed the door and stood in front of her. Before I could take off my shoes, Miyu hugged me. Caught off guard, I froze. She sniffed me and then looked up.

“You smell like a woman.”

“Ah, uh… that’s… I didn’t do anything wrong!”

I ended up being physically close to three girls, so I’ll apologize later. But first, I need to do what I came here to do.

“Onii-chan, I’m hungry.”

“Oh, right. I’ll make something.”

Despite my resolve, I had to feed my sister first. I washed my hands, went to the kitchen, and pondered the fridge’s contents. Given the time, I had to convey my answer while cooking.

Miyu was on the sofa, focused on her game. This morning, she’d been affectionate, making it easy to talk. Now, it was all on me.

But Miyu knew what was coming. In the next few minutes, I’d make my move. Even if it felt abrupt, she’d understand.

“Miyu, come here for a second.”

She immediately put down her phone and came to the kitchen. She stood in front of me without a word. At this point, she knew. All that was left was for me to speak.

When Miyu confessed, my heart swelled with joy. But thinking about being with her, I saw only unhappiness. I truly loved her, so I thought I should choose what made her happiest—a path without me. That belief was my greatest shackle. Looking around, I realized I was in a blessed environment, capable of growing strong.

I want to live proudly as myself. I’ll probably struggle with confidence again, but I’ll remember that Miyu fell for me. That’s my absolute confidence.

“Miyu.”

She’s slightly shorter, her eyes meeting mine.

“Yes.”

Her usual clear, concise response. I love everything about her.

“I’ll make you happy for the rest of your life.”

Words I couldn’t say honestly before.

Miyu smiled softly, still looking at me.

“I’m counting on you.”

Her smile was like a blooming flower. Miyu had accepted the idea of living with me, and I was so overjoyed that I instinctively hugged her.

Unusually, I could smell her sweat, a scent that wasn’t from shampoo or fabric softener. Her unique smell made my heart race. The pure joy of our hearts connecting and the excitement of holding a girl made me want to kiss her for the first time.

“Mi… Miyu…”

But I’d never kissed a girl, nor imagined it. I didn’t know what to do, and my voice was barely audible.

There’s no need for a preamble before a first kiss. But forcing it felt wrong too. Should I close my eyes and pout my lips? That felt weird even to me.

Lost in thought, I froze, still holding Miyu. But staying like that felt unnatural, and I couldn’t act on impulse. I released her. Then, Miyu grabbed my collar and pulled my face toward hers.

“This is how it’s done.”

She raised her face, our noses almost touching. Our eyes met, and without hesitation, she gently pressed her lips to mine.

Our most temperature-sensitive organs touched. There was no taste of first love. Just the sound of air escaping, a hint of saliva, and the fact that we’d kissed.

“Ah… oh…”

My heart fluttered like a virgin’s, having my first kiss stolen by such a bold sister. My chest ached with excitement. I used to mock the perverts in the group, but no man could resist this sister.

“Got it?”

“Y-yes. Very educational.”

The living room clock showed past eight. Miyu didn’t mention our earlier conversation, and I felt relieved that this was the right answer.

Naturally, we headed to the bathroom, washed up, and soaked in the tub in our usual positions. Miyu’s body is incredibly sexy. Thanks to her reclusive nature, every part of her is flawless, petite yet perfectly proportioned. And her monstrous breasts, as always, dominated my view.

“Miyu.”

“No.”

Now that we’re a couple, I thought it was time. But since she hates being touched because it might make her breasts bigger, I couldn’t force it.

“But Miyu, fat breaks down when massaged, right?”

“I know, but I feel like you’d make them bigger. And you’d probably want them to grow while touching them.”

“Can’t deny that.”

True, I can’t deny it. Bigger breasts are great.

“But maybe your breasts grew because you cared too much about them?”

“Hmm… maybe. But I think it’s mostly because you want to touch them.”

She sees right through me, but maybe I can push it.

Wait, no.

“But Haruka touches them, right?”

If Miyu’s breasts grew because Haruka touched them, my theory falls apart.

“Haruka doesn’t touch them much.”

“Really? I thought she developed them quite a bit.”

“She’s the type to make my body super sensitive, not rough handling. No intense rubbing or squeezing.”

“I see.”

So that’s why her neck and thighs are so sensitive. Maybe her breasts are sensitive only on the surface. I’d like to check, but now’s not the time. My top priority is to touch her breasts.

“So, you’ve barely been touched?”

“Right. Girls often grope each other at school, but I don’t join in.”

Miyu would probably get mad if I did. And her friends’ groping sessions seem to go beyond just touching.

“So…”

“Ugh… fine. You can touch, but if you go for the tip, I’ll slap you.”

Got permission! I’m learning how to push Miyu’s buttons.

I held my breath, slowly moving my hand from her stomach to her chest, careful not to touch the tip. I savored her breasts from the bottom, feeling their weight and softness.

Their shape, the buoyancy in the water, the softness of the flesh, and the condensed elasticity—everything amazed me. Holding her heavy breasts in my hands, my heart trembled.

“Mmm…”

Unaccustomed to the contact, Miyu let out a soft moan. During the accidental grope before summer break, I was too nervous to enjoy it fully. I never knew Miyu’s breasts were this erotic.

“Ah… you’re making them bigger already.”

I was, of course, erect, my hardness a tribute to her breasts.

But then, everything changed with Miyu’s next words.

“Did Yamamoto-san do a lot to you?”

There was no malice in her tone, but I was stunned and let go.

“Did you… have sex with Yamamoto-san?”

“No. I was just late coming home, and my shampoo smelled different because I took a bath after sweating. It’s complicated. We didn’t do anything like that.”

“……Huh?”

Miyu looked flustered at my answer.

“Don’t I have your trust?”

“That’s not it. You went to Yamamoto-san’s house today, right?”

“Yeah, after Yuka called.”

“But you didn’t have sex? She didn’t even try to seduce you?”

“We didn’t do anything like that… I think.”

Was her immediate physical contact an attempt to seduce me? If so, why is Miyu anxious that we didn’t go further?

I assumed everything today was within Miyu’s expectations. But her reaction suggests otherwise.

“……This isn’t what we agreed on.”

Miyu muttered, deep in thought. She and Yamamoto-san had made some agreement, likely during their talk three days ago.

“Did I do something wrong?”

If we broke an agreement but didn’t have sex, shouldn’t that be a good thing?

“Earlier, Yuka messaged me, saying you owed her a big favor.”

“Yeah, sorry about that.”

She always ruins the moment.

“That’s fine, but… you turned down Yamamoto-san, right?”

“Yeah. I told her Miyu’s my top priority, so I can’t flirt with her anymore.”

The situation was complicated, so I told Yuka I’d been confessed to, even though Yamamoto-san hadn’t directly declared her feelings.

“Wait, did you completely reject Yamamoto-san?” Miyu asked, making my heart skip uncomfortably.

“I made it clear that her feelings for me wouldn’t benefit her, for her sake and ours.”

For Yamamoto-san’s sake, and more importantly, for Miyu and me.

“……I see. Hmm.”

Miyu seemed to grasp the situation, nodding thoughtfully. Then, she suddenly looked satisfied and hugged me tightly from the front. Her breasts were squished against my body. This was the view when holding Miyu skin-to-skin.

“I guess I made you too much of a good guy.”

“R-really? Is that… a good thing?”

“Yeah. A happy miscalculation, though it’s become complicated.”

Miyu had her own plans, it seemed.

“Well, it’s just doubling similar tasks. No big deal. Good work today, Onii-chan.”

Miyu patted my head. Being hugged and praised by this naked angel erased all negative feelings.

“What should I say to Yamamoto-san?”

“Leave it to me. If you follow my instructions, you can make up with Yamamoto-san and freely flirt with me without worries.”

“That’s perfect.”

I’d do anything to flirt with Miyu. I had many questions about the secret agreement with Yamamoto-san, but since I can’t lie, knowing the plan might reduce its success rate, so I didn’t ask.

“Just to confirm, is it okay if I do something naughty with another girl?”

“Absolutely not.”

“Not even a little?”

Miyu’s earlier reaction seemed contradictory, but in her scenario, I was supposed to have sex with Yamamoto-san in that room, settling things.

“But Yamamoto-san already likes you, and you acted flirtatious with her. Even though you chose me, there’s a way to take responsibility, right?”

“You’re right.”

I’d pushed her away for Miyu’s sake, but it was a lousy way to reject her. I couldn’t imagine talking to Yamamoto-san in class after summer break.

“So, I’ll give you some special training. Sit here, Onii-chan.”

Miyu pointed to the edge of the tub. I stood up and sat where she indicated. My knees were between Miyu’s naked body, and my lower half was far from calm. Then, Miyu took my half-erect penis into her mouth.

“Oh… ah…”

Being licked while semi-erect felt incredibly good, though I’d fully erect quickly and couldn’t enjoy it for long.

“Mmm… jup… mchu…”

Miyu used more saliva than usual, stroking my penis to check the friction. She dripped the remaining saliva on the tip, then leaned forward slightly.

“Don’t cum without permission.”

Miyu lifted her ample breasts with both hands, sandwiching my penis from either side. With each movement of her chest, their weight pressed against my waist. Her breasts stroked my penis, the saliva making lewd squelching sounds, overwhelming my self-control.

“M-Miyu!? Is this okay!? Using your breasts like this…!”

“It’s necessary. It’s unfair if I just give orders without sacrificing anything. How does it feel? Good, Onii-chan?”

Miyu licked the tip of my penis, still sandwiched between her breasts.

“Ah… it feels amazing… so good…”

“Hmm… hiryuu… herro… nnn. Better than Yamamoto-san’s?”

Miyu’s sudden question made me break out in a cold sweat.

“Why ask that?”

“Because you came a lot with Yamamoto-san’s breasts, right? Was it good?”

“Ah… well, both feel amazing…”

“That’s not enough. Say which one’s better clearly.”

Miyu persisted, continuing the fellatio and breast job. The pleasure was overwhelming, and I felt close to cumming before answering.

“Ah… aah… Miyu, I…!!”

I was about to ejaculate, releasing a massive load into Miyu’s breasts, as if planting my seed.

“If you cum without answering, I’ll never do this with my breasts again.”

“Eh…!? No, please… ahh…!”

Miyu glared at me, intensifying the breast job, squeezing my penis tightly.

Pan! Pan! Pan! Her breasts pounded my penis relentlessly. The splashing sounds echoed in the bathroom. My ejaculation reached the base of my urethra, yet Miyu’s soft flesh enveloped my entire penis, mercilessly stimulating my sensitive spots. There could be no greater pleasure than this.

“Ahh… amazing…!! Definitely better than Yamamoto-san!! Aah… Miyu… I’m cumming… cumming!!!”

Biyu! Dobiyu! Gpiyu! Biyu! Biyubiyu!

I ejaculated a massive load into Miyu’s breasts. The sticky fluid burst from her ample chest, too much to contain.

“Haa… haa…”

Though Miyu had been the one moving, I was the one gasping for breath. My heart raced as if my blood had been drained.

“How was it?”

Miyu spread her breasts, playing with the sticky residue of my ejaculate.

“It was amazing, but… I feel just as guilty…”

“From now on, you’ll have to say which of us feels better before cumming. It’s part of making up with Yamamoto-san.”

“Ugh… I’ll try…”

I had no idea how this would help make up with Yamamoto-san, but the training ended there. We left the bath together.

After changing into pajamas, Miyu came to my room. We got into the same futon, warming each other with our body heat.

“Onii-chan.”

Miyu snuggled close. Shy Miyu was a bit bolder in the dark.

“I’m so happy.”

Hearing her say that again, I hugged her back, nodding. Making Miyu happy is my greatest joy.

We’re both in love now. There are still challenges, but we’ve taken the most important step.

We’re siblings and lovers. Miyu no longer seems to care that I’m her real brother. I don’t plan to prioritize only physical desires, but it’s necessary for building a healthy relationship.

“Miyu…”

Now’s the time to ask.

“Do you still care that we’re siblings?”

I never cared that she’s my real sister. I never even questioned it, which might be an issue.

“What kind of question is that?”

Miyu pressed her chest against me, smiling.

“Do you think it’s okay to have sex with me now?”

“I’ve been wondering when you’d ask.”

Miyu answered playfully, yet shyly. Nighttime Miyu is indeed bold. Since I’ve always initiated our intimate moments, I should lead the way for sex too.

“But, Onii-chan…”

Miyu continued, addressing a crucial point beyond our feelings.

“Make sure you understand what I said this morning before asking.”

Miyu closed her eyes. This morning, she mentioned that sex would require caution… specifically regarding that.

Miyu’s sex drive becomes abnormally heightened when we’re intimate. If we had full intercourse, what would happen? If I acted on my desires without restraint, what would become of us?

Seriously considering it, the implications were daunting. Miyu might lose control of her desires, begging for sex daily. If we attended the same high school, we’d likely abandon studies for constant sex.

“……I understand, Miyu.”

Miyu wants it too. As her brother and lover, I must handle her desires carefully, finding what’s best for us. I’m the only one who can make her happy.