My Little Sister Is the Best F*p Material

Volume 7 Chapter 01: Rainy Days Suit Sibling Sex Perfectly

The sound of rain tapping on the window woke me to a darker-than-usual morning. My lungs felt strangely constricted, the cause being Miyu, sprawled across me as she slept. I’m honestly impressed I managed to sleep through the night under her weight.

Miyu and I have shared countless mornings, but with each passing day, we’ve grown closer, until now there’s no distance left to close. Being clung to by Miyu, whose entire body—especially her chest—is soft and squishy, is pure bliss. But with my blood vessels compressed and tingling, I doubt I can endure it much longer.

“Nn… it’s Onii-chan. Morning.”

Miyu murmured, her eyelids fluttering open to confirm I was the one beneath her. When she’s deep asleep, even shaking her won’t wake her, but somehow, in the morning, she syncs with my consciousness and stirs.

“Morning, Miyu.”

I managed to reply, squeezing air through my narrowed airways.

“Another day with Onii-chan…”

Still half-asleep, Miyu brought her face close, her lips grazing my neck before sucking hard, like a vampire.

“Hey, Miyu!”

I gently peeled her off after she left a bold hickey.

“You marked me as yours, so what’s one or two hickeys from me…?”

She trailed off, her eyes widening as if realizing something. Come to think of it, beyond the spot she just kissed, my entire neck felt an itchy, unfamiliar sensation.

“One… or two…?”

Miyu tried to brush it off, but it was obvious she’d left multiple hickeys while I slept. The swollen feeling on my neck suggested at least five, plus several bruises below my collarbone.

“When did you do all this?”

“Here’s the thing—I don’t remember at all.”

She said with a blank, innocent expression. She didn’t seem to be lying. Apparently, a half-asleep Miyu went to town kissing me while I was out cold.

“What kind of mood leads to this many hickeys?”

I tapped her back, signaling my breathing was at its limit, and rolled her to the side. To kiss so many spots like that, she must’ve been in a lovesick frenzy that would make even the sappiest couples blush—a one-sided, overwhelmingly affectionate display.

Why didn’t I wake up for that? Miyu might’ve been clinging to me, whispering syrupy sweet nothings that’d make you gag, kissing me over and over. As I pondered this, I noticed Miyu giving me a cold stare.

“No perverse fantasies about your sister.”

“I’m just imagining your cute, lovey-dovey side.”

“I definitely didn’t do whatever you’re thinking.”

Miyu suppressed her embarrassment and pouted. Her body’s become more honest, but she hasn’t fully shed her dry demeanor. That’s part of her charm, though.

“You’d have to really love me to kiss me this much.”

“Stop, stop! That’s too cruel…”

Miyu covered her face with her hands, her long hair flailing down to her waist. For someone who left hickeys in a daze, she was surprisingly alert now—maybe even a bit aroused. She might be pent-up.

“Here’s the reality.”

She said, climbing back on top of me, diving in a way that perfectly jabbed my solar plexus. The intensity was endearing, a cover for her shy affection.

“This is revenge for taking my first time…”

She muttered, sucking hard on my neck again. Her breasts, pressed flat against me, spilled out elliptically.

My little sister’s erotic body had my groin swelling since morning. She must’ve felt the hardness against her, but by now, Miyu doesn’t even comment on my erections.

“Any qualms about morning sex, Miyu?”

“Hm? Wanna do it?”

Dismissing her “revenge” talk, she grabbed a condom from the bedside and showed it to me.

“Not just want—I’d like to, or rather, I’d be good with just coming.”

“I see. Well, use me as you please.”

With a casual reply, Miyu tore open the condom packet and handed it to me. “Use me as you please” referred not to the condom but her body. This prim, aloof honor student, with her cool, unapproachable eyes, finds supreme joy in being used for her Onii-chan’s sexual relief—a severe case of brother complex.

“I don’t mind doing it in the morning, so just say if you want to.”

Thanks to her physiology, cuddling with me gets her wet, and her abundant saliva means her mouth never dries out, even upon waking. She’s ready for blowjobs or sex right out of bed.

“Should I finger you a bit first?”

“Nah, just put it in.”

With that, Miyu slipped her fingers under her culottes, shifting her panties aside. Apparently, we’re doing it clothed. Without a word, I put on the condom and slid my penis into her.

“Fuu…”

Miyu exhaled softly to ease the sensation as I entered. Her vagina was so tight I could feel the warmth and texture of her walls.

“Onii-chan, it could’ve been a bit smaller.”

“Guys compare sizes, you know—it’s a thing.”

“You get to sleep with me, so that alone should be something to brag about.”

“True enough.”

We slipped into casual conversation despite being connected. Miyu tilted her head, her expression asking, “Not moving?”

“Hoping you’d take the lead in cowgirl.”

“No way, that’s too much like some lewd girl.”

Even after our wild nights, Miyu refuses to admit she’s a “lewd girl.” Maybe she excuses her raw lust as instinct running wild, so it doesn’t count.

We’re both waiting for the other to move. I don’t mind taking the lead, but when she’s in a position to move freely, it’s only natural for a guy to want her to take charge.

“Just think of it like playing with a dildo. No need to seductively grind your hips.”

“Onii-chan started this because you wanted it. Shouldn’t you be the one moving?”

“Fair point…”

Outsmarting Miyu verbally is tough. Still, I really want to experience her in cowgirl. If I start thrusting, she’ll give in to pleasure and switch to sex mode. If I stop, she might move on her own.

But no, that’s not it. I want to see her move her hips shyly while she’s still rational.

“Won’t you move?”

“Nope.”

Our standoff continued. My inserted penis, squeezed by her tight vagina, strained to stay erect as my lower abs contracted, pumping blood.

“Nn, ah, wait—don’t twitch!”

“Don’t ask the impossible. Your tightness is already making my veins itch.”

“Ugh… but still…”

Staying still inside her, my penis pulsed as if ejaculating air, sending blood to the corpora cavernosa, temporarily swelling it. That stretching sensation seemed to frustrate Miyu with teasing pleasure.

“Fuu… It’s, uh, raining today, huh. What should we do? Date tomorrow, maybe?”

Miyu threw out a random topic to distract herself. We haven’t had a proper couple’s date, and it’d be nice to go somewhere during summer break.

“Where do people go on dates? Karaoke, aquarium, amusement park, right? Are you bored of those, Miyu?”

“No way. Anywhere with you would feel fresh. So, like, an aquarium might be nice… it’s cool there…”

Breathing heavily, Miyu grabbed her phone to talk. She seemed to be looking up nearby aquariums. My penis was still inside her.

“This Nishi-Kaihin Aquarium in Tokyo got renovated this summer. It was packed right after summer break started, but it might be less crowded now.”

“Sounds good.”

I took the phone from her, browsing the website. I haven’t been to an aquarium since I was a kid—can I make it fun for her? I don’t know much about fish, and I’m still new to dating. Maybe a dolphin or penguin show would make a good memory.

“There’s a hot spring nearby too. Can they build one next to an aquarium?”

“It’s not a hot spring, it’s a spa. Nn… it’s part of a nearby amusement complex…”

“Got it.”

I fiddled with the phone, searching for date spots. Miyu, still in cowgirl with my penis inside, initially distracted herself well, but her breathing grew ragged from keeping it in so long. My arousal was spiking too, and my penis twitched more frequently inside her, making her grimace with pleasure while she desperately tried to act calm.

“Fuu… Okay, the aquarium and spa it is, right?”

Staring at nothing by the bed’s edge, Miyu tried to ignore the sensations in her vagina but finally gave in, clinging to me.

“Onii-chan, move. Please…”

Her desperate plea left me no choice but to give in. Being begged for sex by my adorable sister? I couldn’t refuse.

I ground my hips in near slow-motion, pushing my rigid penis deeper, spreading her tight walls. As the tip neared her cervix, Miyu’s reactions intensified.

“Ah… aah…!!”

I ground my hips in near slow-motion, pushing my rigid penis deeper, spreading her tight walls. As the tip neared her cervix, Miyu’s reactions intensified.

“Ah… aah…!!”

Letting out an embarrassingly loud moan, Miyu’s face flushed bright red. Still, I didn’t stop, savoring her wet, lewd flesh as I thrust my penis deep inside.

“N-no, hiyah, that’s bad… slow is bad…!”

When I entered slowly, Miyu felt every detail of my penis, making the stimulation too intense. Apparently, a faster pace made the pleasure more bearable for her.

I continued with steady, unvaried hip movements. Yet, her hole made lewd, wet sounds, amplifying her shame and heightening her pleasure.

Reaching the sensitive spot just before her cervix, her body trembled violently, but she still didn’t climax, despite it being reasonable for her to have peaked multiple times already.

“Hau… hia… so embarrassing… make me come already…”

Miyu pleaded with a teary face, and I pondered what to do. I wasn’t trying to be mean, but she just wasn’t getting there.

Thinking it over, I recalled that Miyu always focused on pleasing me. Even now, when I make her climax, it’s usually after I’ve ejaculated. So, instead of pampering her, switching to sex where we both feel good together might push her over the edge.

“Miyu, I’m gonna come too.”

I wrapped my arms around her, restraining her, and shifted to selfish thrusts, like using her vagina to jerk off. Rubbing sensitive spots like the glans and frenulum against her tight flesh, I prepped for ejaculation.

“Aah… hii… nnaah, ah… Onii-chan…!”

Miyu let out sultry moans, her vaginal walls writhing tightly. Her full-body convulsions and gasping breaths showed she was nearing a genuine climax, no act.

“It feels so good, Miyu… so tight, it’s amazing…!”

Like fucking a love doll, I thrust in and out repeatedly. The more I chased pleasure, the higher her sensitivity climbed, her expression melting into joy. Miyu once said sexual release and semen disposal were separate—for her, being used solely for sexual relief was uniquely special.

Despite our many intimate moments, there’s still so much I don’t know about her. Each discovery makes her more adorable, and I love her from the bottom of my heart. I want to use her for my sexual needs more, entrust all my lust to her, and have her drain me until I’m dry.

“Nnah, ah…! Onii-chan’s… getting bigger again… I can’t… no more… aauuah… nna Aaah…!!”

“Miyu… I’m gonna come… here it comes… Miyu…!”

“Nn, aah… Onii-chan…! Kihye… aahn… ah… nhyaaa…!”

With each spurt, her vaginal walls pulsed, as if sucking up my semen. This sister, who loves my cum, finally released her pent-up lust, collapsing onto my chest with a faint sheen of sweat on her forehead.

“Haa… fua… we really went at it from the morning…”

Miyu, face flushed like after a hot bath, went limp. When I pulled out my still semi-hard penis, she let out a small, “Nn,” sexy moan, biting her lip in embarrassment.

“Getting to have sex with my cute sister in the morning makes me so happy.”

I stroked her head and laid her beside me. Since we did it clothed, removing the condom and wiping the semen returned us to our pre-sleep state.

“Good thing your little sister’s cute, huh?”

“Now I just pray this daily life isn’t some dream from stumbling into a game.”

“All the games you had were sister-themed, after all.”

Our pillow talk lacked modesty, but I exhaled the pleasant fatigue deeply. As I moved to tie the condom and wrap it in tissue, Miyu hurriedly grabbed my arm.

“Don’t tie the condom—let the contents soak into the tissue. If I lose my mind, I might secretly use it.”

Sex with Miyu requires utmost care. Her libido, amplified by reproductive instincts, carries a high risk of unintended pregnancy.

“You don’t want to get pregnant with the sperm I shoot directly?”

There was no deep meaning behind my question. My eroge-warped brain thought that, like during her first time, Miyu’s desire for manga-like impregnation wouldn’t be satisfied with semen squeezed from a condom.

“Ah… right. That’s true.”

Miyu instantly latched onto my words, gripping my hand.

“With that mindset, we’re probably fine. I won’t get pregnant unless it’s Onii-chan’s semen shot inside me. If Onii-chan orders me to ‘get pregnant’ while coming, that’s when I’ll conceive.”

“Got it.”

Her oath was something only an ex-otaku like me could understand—normal people would be baffled. Studying sex through eroge was probably a mistake. But I doubt Miyu would break such a clearly stated promise, and it’s a relief she won’t secretly use my semen.

“By the way, what was so great about sister-themed stuff?”

Miyu picked up the earlier conversation.

“Hmm. Maybe because sharing time with them feels natural.”

On reflection, I wasn’t drawn to the sister archetype itself.

“No awkwardness being with a sister?”

“To get close to a cute girl, you need some serious talent, right? I was a bundle of complexes, so I couldn’t relate to those protagonists.”

Even stories where enemies become friends through fights felt off—why would a heroine waste time bickering with a guy she dislikes?

As I explained, Miyu nodded solemnly.

“So Onii-chan’s weirdly calm because, despite not being popular, you had a cute, sex-cooperative sister?”

“That’s a big part of it.”

“But Kanade-san and I are the ones using Onii-chan for our convenience.”

“I know. You’ve told me plenty. It’s just my feelings haven’t caught up.”

I never denied Miyu’s values or Yamamoto-san’s past—it just turned out that way. Yet they insist it’s my personality. I’ve stopped undervaluing myself, but truly grasping this will take time.

“Seeing how hooked Kanade-san is shows your charm.”

Miyu smiled gently, tapping my sternum with her middle finger. With both of them so fond of me, all I need is to build confidence.

“Speaking of Yamamoto-san, will the reconciliation plan work like this?”

“Of course. Our occasional cuddling is part of the strategy.”

“Oh, really?”

“Yup.”

Miyu stared at me with a meaningful look.

“So the cuddling is just part of the strategy?”

To confirm, I asked again.

“No, well, it’s not a small part of me wanting to do it. But if I don’t frame it as part of the plan, I’d die of embarrassment.”

“Why not just be honest there?”

Since she started swallowing my semen, Miyu’s sensibilities have been enigmatic. All the cryptic things she’s said were probably chosen with her own peculiar logic, perfectly reasonable to her.

“You know how my brain goes haywire every time I get embarrassed, right?”

So she’s self-aware.

“That’s why, to keep the plan on track, I can’t just slip into ‘I love Onii-chan’ mode so easily.”

“I see…”

For Miyu, living true to herself and upholding duty are one and the same. Even if she’s burning to cuddle freely, she reins herself in until her goals are met. That’s the authentic Miyu she described.

“Once the strategy’s done, will I get to see the Miyu who easily goes into ‘I love Onii-chan’ mode?”

“Don’t get weird expectations.”

She scolded me gently but firmly. My guarded little sister got up from the bed, stretching with a big yawn.

“I’ve finally found something to give back to Haruka. This’ll be the final battle for both of us.”

Miyu clenched her fist with resolve. Come to think of it, Haruka had asked me to let her sleep with Miyu. She said it wouldn’t last long, but I didn’t expect it to end this soon.

“Something to give back? Sewing-related?”

“No way. Haruka won’t be satisfied with anyone but me. But I can’t sell my body anymore, so all that’s left is to sell my soul.”

“Your soul…!?”

That sounds like things are getting worse. What does selling her soul even mean?

“For now, let’s have breakfast.”

Miyu opened the curtains, squinting at the morning light. She didn’t seem inclined to share more details, so I quietly followed her downstairs.

This morning, Miyu was on cooking duty. Wearing an apron, she grilled salmon and made a classic Japanese breakfast.

“Hey, Miyu, what’s the point of cuddling with me for the strategy?”

To restore my old relationship with Yamamoto-san, whatever we do next will likely be the final push. Yet, every time I meet Yamamoto-san, we only grow closer, and it doesn’t feel like we’re heading toward a resolution where we stay just friends.

“Most of your experience with women is sexual, right?”

“Skipping dates and going straight to sex, yeah.”

“In other words, you’ve got plenty of sex experience.”

“So, because I lack experience with couple-like affection, it’s time to train in that?”

“Exactly.”

The logic makes sense, but the cause-and-effect is unclear. How does this lead to staying friends with Yamamoto-san?

“What’s your most affectionate memory with Kanade-san?”

“Hmm… let’s see…”

My most recent memory with Yamamoto-san was having sex at karaoke or on the bus, but that was more about mutual lust than affection. The date at the department store stands out as a vivid, affectionate memory.

“The day Haruka called me, I met Yamamoto-san and we wandered around the department store. It was… you know…”

I started, but my tongue stumbled. That date was comparable to what couples do, but Miyu was always on my mind, and the awkward moments left a stronger impression.

“No, wait. Probably the week I stayed at her place, back when I was desperate to get a girlfriend besides you.”

I chose Miyu in the end, but without that call from her, I might’ve ended up dating Yamamoto-san. That week, our emotional distance shrank significantly.

“Yamamoto-san’s place had hardwood floors, so we’d always sit close together when eating. That’s probably it.”

“I see, I see. Let’s do something like that now.”

Miyu started moving dishes from the kitchen table to a lower one, so I helped, arranging them to sit side by side. Doing something similar—does that mean she’ll feed me with an “aah”? Seriously?

“You’ve said this before, but this is for Yamamoto-san’s strategy, right?”

“Of course. I owe Kanade-san, and I love her too. That’s why I won’t compromise. If we’re doing this, we do it thoroughly.”

Miyu knelt on the carpet, smiling up at me.

“So I should treat Yamamoto-san the same as before?”

“Dates, sex—whatever Kanade-san wants.”

Miyu nodded without hesitation.

“We’re already pretty intimate…”

I finished moving the dishes and sat beside her. A house has more space than Yamamoto-san’s room, so it’s not an exact replica, but having Miyu next to me felt right.

“That’s fine, Onii-chan.”

Miyu answered confidently.

“There’s a spell on Kanade-san. So just be yourself and cuddle with her however she wants.”

“A… spell?”

“That thing you know about. If you haven’t noticed, I won’t tell you.”

Cutting off there, Miyu picked up her chopsticks and flaked the salmon.

If the strategy is to let Yamamoto-san do what she wants until she’s satisfied, I can see there’s no resolution beyond that. With our bond only deepening, even if she decides to end things, it won’t be without sadness or lingering feelings. Staying in the post-breakup state would’ve been better.

This strategy is as much about improving my relationship with Yamamoto-san as it is about Miyu upholding her pride. I can’t believe Miyu, who honors duty even at her own expense, would resolve this by forcing me to give Yamamoto-san a “boyfriend experience.”

“Well, don’t overthink it. Isn’t it an easy job to just cuddle with a cute girl?”

Miyu picked up a piece of salmon with her chopsticks, holding her other hand as a catch, and offered it to me. She’s really going to feed me.

I’m curious about this “spell” on Yamamoto-san, especially since it’s something I supposedly know. But for now, cuddling with Miyu comes first. No, there’s nothing more important than that. Alright, time to cuddle with Miyu!

“Here, Onii-chan. Aah.”

Miyu brought the chopsticks forward with surprising enthusiasm, and I got into the mood too.

Opening my mouth, she fed me, making me feel almost regal. Maybe because Miyu reveres me as her master?

“Delicious. No matter what I eat outside, this taste hits home the most.”

It’s not like she uses premium ingredients, but Miyu’s cooking is delicious. Years of cooking together mean she knows my tastes perfectly.

“Your cooking feels the same to me, Onii-chan.”

I sipped miso soup, and Miyu placed salmon on rice, feeding it to me. If she feels the same about my cooking, that’s heartwarming. Getting culinary praise from Miyu, who’s traveled the country, is especially rewarding.

While I chewed, Miyu ate her own food, and after about half, we returned to eating separately.

“Would a spoon have been better for feeding?”

“If you’re offering, I’ll take it.”

“Then let’s do dessert.”

Miyu stood, grabbed a pudding from the fridge, and returned with the cup and spoon, watching me eat while kneeling.

“Should I finish this meal first?”

“Please do.”

Miyu waited for me to finish breakfast, looking as loyal as a puppy. She’s almost godlike in her objective clarity, but when it comes to her own romantic feelings, she’s adorably clumsy.

If I dawdled, her food would get cold, so I wolfed down the rest of my meal.

“Alright, I’m ready.”

It felt a bit backward to eat quickly just to be fed by her, but going along with this mysterious strategy was fun. As a way to spend a rainy day with a lover, it wasn’t bad.

“Onii-chan, aah.”

The pudding, coated in caramel sauce, slipped into my mouth, melting with a subtle eggy aroma and spreading sweetness. After one bite, Miyu prepared the next, waiting for me to swallow before feeding me again.

“Delicious?”

“Really good.”

“Then I’ll have some too.”

Miyu scooped another bite, stared at the spoon for a few seconds, then popped it into her mouth.

“What’s up?”

“Nothing. Just thought about indirect kisses.”

“To get shy about that now…”

But I get it. Things feel different through a medium. Even a girl fine with oral ejaculation might not want to drink it from a cup.

I let Miyu feed me until the pudding was gone, enjoying a couple-like moment, but compared to Yamamoto-san, something felt lacking. Miyu seemed to feel it too, and we both tilted our heads, puzzled.

“Maybe it’s because you’re not embarrassed enough, Miyu.”

“What kind of embarrassment do you expect from me?”

Miyu narrowed her eyes, bracing herself. That’s when I finally felt her true charm.

Yamamoto-san’s nurturing, motherly nature makes being fed by her so intimate. Even Miyu can’t match a genius in that field, so we need to consider specialties.

“It’s about cuddling, right? Couple-like, something no one else can satisfy.”

As I spoke, Miyu munched her food, swallowing it down.

“For example, if you went, ‘I love Onii-chan, chu-chu,’ probably no one could top that.”

“That’d kill me.”

With cold, calm precision, Miyu shot down my suggestion. But by the time breakfast ended, she seemed to have sorted it out and faced me again.

“So, specifically, what do I do?”

I pointed to the small red marks on my neck.

“Just do what you did when you left these hickeys.”

“I didn’t go ‘I love Onii-chan, chu-chu’ when I left those hickeys!!”

Miyu denied it fiercely, but since she doesn’t remember, the possibility’s not zero—I’d say it’s high.

“Then fake it. Just give me pretend chu-chu kisses around these hickeys.”

“The phrase ‘chu-chu’ is already gross…”

Miyu sighed, gave me a disdainful look, turned away with another sigh, glared at me from a distance, then sighed a third time in resignation.

“Fine, I’ll accept that idea.”

She actually agreed.

We cleaned up the dishes, brushed our teeth, washed our faces, and returned to the living room, sitting on the sofa. Before starting round two of the cuddling strategy, Miyu took a deep breath to steady herself, then knelt and leaned in close.

“Here we go.”

With a sulky face unbefitting a cuddly couple, Miyu kissed my neck. As her lips parted with a chu, we stared at each other silently, deadpan. She seemed to get what I meant, her eyebrows twitching in annoyance. Then, with a resigned air, she brought her lips close again.

“O-Onii-chan, I love you—”

Muttering like a curse in a tiny, monotone voice, her delivery was awful. Even if it’s just for show, this won’t do.

“You’re missing the key part.”

“Onii-chan, I love you, chu-chu! Nn-mu-chu!”

In a reckless frenzy, Miyu kissed my neck and cheeks. I want her to act more couple-like, as intended, but she’s so cute like this, I can’t stop her.

“I’m really loved, huh?”

“No kidding.”

Miyu blinked her big eyes.

“Onii-chan, what’s the clearest sign to a guy that a girl loves him?”

“A sign of love? Hmm…”

From a girl’s perspective, it’s being told they want to be together or sharing memorable things. But for a guy, the first thing that comes to mind is being allowed physical intimacy.

“And, Onii-chan, doesn’t sitting here remind you of anything?”

“Remind me? Is it related to your question…?”

Confused, I scanned the room for answers. Nothing visible stood out, but being on the sofa did jog a memory.

“Oh, that envelope.”

I’d gotten a mysterious small Western-style envelope from Miyu. Maybe its contents—a note about sex precautions—relate to Yamamoto-san’s “spell.” I grabbed my wallet from the pouch hanging on the coat rack by the entrance and pulled out the stamp-sized letter.

“Can I read it?”

“Yeah.”

I took out the small paper and read Miyu’s short message. My thoughts froze for a moment at the words written there.

“I’m on the pill, so we can have sex without a condom.”

The message was so unexpected I thought I was hallucinating. But no matter how many times I shook my head and reread it, the note clearly said she’s taking the pill, so we can have raw sex and I can ejaculate inside her.

“W-What’s this?”

“A creampie permit?”

Where did she learn that term? Wait, was it in one of my games? I need to deeply regret my tainted past.

“I don’t even know where to start… Why put this in a letter?”

Was she too embarrassed to say it? This is a big deal that affects our future, and we should discuss it properly before going raw.

“There are lots of reasons. Do you remember what I said when I gave it to you?”

What she said when she handed me the letter? I’d forgotten until she asked, but she specifically said, “This is from the rational me.”

“Since we started having sex, if I suddenly said I’m on the pill and you can come inside, wouldn’t that seem suspicious? Like I’m lying to get pregnant?”

“You could’ve told me beforehand.”

“There’s a lot to that too.”

It’s not that simple, apparently.

“I don’t know how much you know, so just to be safe…”

The pill also stabilizes menstrual cycles, so it’s typically started after a period. If ten days have passed since ovulation, raw sex is safe even before starting, but Miyu’s cycle is too unpredictable, and her reproductive instincts are so strong that half-baked raw sex before the pill takes effect is extremely risky.

Plus, she needed to test if her rationality could handle sex, starting with condoms. That’s why she didn’t want to give me unnecessary info before our first time.

“There are other reasons too, but let’s say it’s for safety and mood.”

I’m curious about the other reasons, but it’s good to clear up one mystery.

“Wait, does this tie back to your first question?”

“Yup. If your little sister lets you come inside her, that’s undeniable proof of love, right?”

What kind of way is that to show love?

“So I can have raw sex with you, Miyu?”

“Not right now. From how it feels with you, I still have enough fertility left to conceive.”

“I’m shocked you can tell that.”

She’s pouring all her reproductive energy into sex with her brother, huh.

“Onii-chan, it’s raining outside.”

Miyu leaned into me, and I lay back on the sofa, going with the flow.

“Yeah, it’s raining.”

In a house without our parents, raindrops curtained the outside.

“Rainy days are perfect for sibling sex, aren’t they?”

Miyu stared at my throat, slowly pressing her lips to it.

“We don’t have to hold back our voices all day today.”

“Idiot. We’re not doing it all day.”

Scolding me with a mix of exasperation and anger, Miyu showered me with kisses like May rain.

“Onii-chan, I love you.”

“I love you too, Miyu.”

As I opened my mouth, Miyu kissed me to silence it, and from there, we devoured each other’s lips, tongues entwined.

In the steamy heat of our close contact, my groin swelled, but instead of demanding sex, I kept fondling her body. Being gently scolded while cuddling like this—I realized that’s what makes us feel like lovers. This unique form of love, born only between me and Miyu, is something I want to cherish now.

“Onii-chan, it’s about time to ravish your little sister.”

Miyu whispered her desire. Does she want sex?

“I was thinking this is time to reaffirm our love.”

“Even so, I’m on the pill, so we won’t need condoms. We bought a ton, didn’t we?”

Miyu pushed hard, not holding back. She really wants sex.

“You said they were there.”

“I just said they’re on the shelf.”

“You’re determined to make your brother a pervert, huh?”

“Part of being a brother is understanding a maiden’s heart that doesn’t want to admit she’s a pervert.”

Saying it out loud defeats the purpose.

“Fine. But don’t get mad if we end up doing it all day.”

“Isn’t there an option where I get mad but still want it…?”