Chapter 1

“…What the hell is going on?”

“That’s my line.”

Overwhelmed with confusion, the two of us had stepped outside, leaving our parents behind. To tell the truth, my relationship with this girl couldn’t be summed up in a single word. And now they tell me she’s going to be living with us starting today? No way I can accept that.

Let me explain things in order. My old man decided to get remarried. I’m in high school already, so I told him to do whatever he wanted and didn’t pry too much into who the woman was. His new wife and her daughter were supposed to move in today, so I was waiting at home.

They arrived. I went to the front door to greet them—

And that’s where everything went wrong.

Because my dad’s new wife’s daughter was someone I knew.

No, let me be clear. It’s not just that I knew her.

We were sex-friends.

The girl now standing in front of me, formerly Yuina Izumi, now Yuina Anjou, and I were in a physical relationship.

“Didn’t the surname tip you off?”

“It’s not like I cared. I didn’t give a damn who Dad was marrying. I didn’t even bother remembering her name.”

I, Hotaka Anjou, had just become step-siblings with my sex-friend.

We first met at a mixer I got dragged into as a numbers-filler. Normally, someone like me—socially awkward and isolated in class—would never get invited to stuff like that.

But that day was different.

A childhood friend bowed his head and begged me to come. I wasn’t really up for it, but I couldn’t turn him down. And that was how I met Yuina.

Naturally, I wasn’t enjoying myself. I was just going through the motions. But while heading to refill my drink at the drink bar, I ran into Yuina—and she spoke to me.

“Hey, Anjou-kun. You’re not having fun, are you?”

“Ah, Izumi-san. Yeah… I’m not really used to places like this.”

“Same here. I only got invited to balance the numbers.”

“But you’re super popular, Izumi-san. All the guys in class couldn’t take their eyes off you.”

She was a stunning girl, no doubt. Long, silky black hair, perfect facial features—she stood out. Someone like me couldn’t help but feel we were on entirely different genetic levels.

“Hmm, I don’t really like guys who come on too strong like that. If anything, I’d prefer someone like you, Anjou-kun.”

“I doubt anyone’s interested in someone like me.”

“Such a downer. You know what? Let’s sneak out of here. If I leave with someone, I’ve got an excuse to go home.”

“Yeah… I’m not having a good time either. I’ll help you sneak out.”

So we slipped out together. I thought we’d just split up after that—

But then she tugged on my sleeve.

“Wanna lose your virginity?”

I was stunned. I had no idea what she meant at first.

“I just got dumped, actually. I need someone to comfort me.”

“And you chose me?”

“Yeah. You don’t seem like the type to jump me or anything.”

“I don’t know… Isn’t it kind of wrong to do that when we’re not even dating?”

“You’re so serious. But that’s okay. I’ll make you bad.”

Just like that, she brought me back to her place.

We both took showers.

And in her room—we lost our virginity.

At first, I thought she was experienced because of how boldly she invited me.

But it turned out it was her first time too.

We were both awkward, fumbling through it, struggling just to get things started.

Eventually, we finished.

Lying side by side on her bed, we started chatting.

“So? How was your first time?”

“Honestly… it felt amazing. I was surprised when there was blood though.”

“You were really gentle, Anjou-kun. The way you touched me…”

“I was just being careful, that’s all.”

“No, you were sweet. I feel kind of… fulfilled now. Say, how about we keep this kind of relationship going?”

“Are you sure? Just sex—nothing more?”

“Yeah. I’m not really in the mood for romance right now. But you don’t seem like you have anyone, either. It’s perfect, don’t you think?”

“Alright.”

And just like that, we became sex-friends.

After a few times, we started calling each other by name—and now we’re here.

“Anyway, we absolutely can’t let my dad find out.”

“Don’t worry. Mom’s kind of dense when it comes to that stuff. I think it’ll be fine.”

“No. We have to stop this. Let’s end it and live as normal siblings.”

We agreed on that and went back inside. Our parents were busy unpacking. I figured I should help, so I took Yuina upstairs to show her the room, then helped carry her luggage back and forth a few times.

When I offered to help her unpack, she said she’d do it herself. So I went back to my room.

Never did I imagine Yuina would become my step-sister.

Since my birthday is April 20th and hers is June 25th, I’m the older one—so I’m technically the “big brother.” We’re the same age, though, since both our birthdays already passed and it’s late August now.

Honestly… I do regret ending things.

Yuina’s body was incredible.

I’d relied on it more times than I can count.

And now that we’re not doing anything anymore, I’ll probably still fantasize about her when I’m alone.

Until now, it was just my dad in the house, so I had plenty of privacy.

But with two more women here, even taking care of myself might become a challenge…

That anxiety weighed on me as I drifted into sleep.

“Wake up.”

Someone shook my shoulder. I opened my eyes—Yuina was standing over me.

I sat up slowly, rubbing my eyes.

“Mom says dinner’s ready.”

“Got it. I’ll be down in a sec.”

I got out of bed and headed downstairs. A delicious smell filled the house.

In the living room, sukiyaki was laid out on the table.

“It’s our first night living together. Gotta go big, right?”

My dad laughed heartily.

Yuina’s mom, Yuni-san, smiled softly with her hand to her mouth and gestured for me to sit.

“Thanks for helping with the unpacking, Hotaka-kun.”

Yuni-san had an elegant, mature charm. I could see why Dad fell for her.

Yuina sat directly across from me and put her hands together to say “Itadakimasu.”

“So Yuina, what do you think of Hotaka-kun?”

“He seems like a good guy. It’ll probably take a bit of time to get used to things, but I think we’ll get along.”

“How about you, Hotaka? Think you’ll manage?”

“Yeah. Yuina-san’s really cute, so I’m kind of nervous, but I think we’ll be fine.”

The usually quiet dinner table became lively and warm.

With conversations flowing and everyone enjoying the sukiyaki, the evening passed peacefully.

After dinner, I went to take a bath—

And found Yuina inside, in the middle of undressing.

She was down to her underwear.

“Sorry!”

“You should’ve knocked… Or—wanna join me?”

She smirked like a devil, teasing me.

That kind of temptation instantly brought back memories of her body.

I shook the image from my mind and turned my back to the bathroom.

But once it surfaced, I couldn’t erase it. It clung to my thoughts.

“Guess I’ll rub one out.”

I went back to my room and secretly took care of myself.

Later, once Yuina was done with her bath, I got in too.

Afterward, I cooled off in front of the fan. That’s when Yuina came into my room in her pajamas.

It was the first time I’d seen her like that. It completely flustered me.

“What do you want?”

“Just came to show off my pajamas.”

She sat on my bed.

“Wanna sit next to me?”

I sat down beside her. The scent of her shampoo wafted over and tempted me again.

“Wanna sleep together?”

“We can’t. If Dad and your mom find out, there’s no way to explain.”

Thank god I relieved myself earlier.

If I hadn’t, I might’ve lost control just now.

Yuina is beautiful. Her breasts are big, and her body is perfectly proportioned—a body that guys love.

That’s exactly why living together is dangerous.

It’s only a matter of time before we slip up.

I should be avoiding her.

And yet, Yuina keeps getting close to me.

“Hey, maybe we should put some distance between us. We don’t want them finding out, right?”

“But suddenly acting like strangers is impossible for me.”

As she said that, she rubbed her hand against my crotch.

She was clearly trying to seduce me.

I clenched my teeth and spoke through the arousal.

“Cut it out. I won’t be able to hold back.”

“You don’t have to.”

“Yes, I do! Dad and your mom are here!”

“If we’re quiet, they won’t hear.”

Yuina flipped a switch and went full seductress.

My eyes were drawn to the cleavage showing through her pajamas.

If I hadn’t rubbed one out, I would’ve been doomed.

I pushed her away and sighed.

“Look, we’re family now. A relationship like that isn’t right.”

Yuina puffed out her cheeks in protest.

“You sure didn’t seem to mind when you were all over me back then.”

“That was then. This is now.”

Hearing someone talk about your own actions is way more embarrassing than I thought.

I forced a wry smile and tried to reason with her.

“Now that we’re family, that kind of stuff is off-limits. That’s the rule if we want to live together peacefully.”

I tried to explain it as clearly as I could—like I was talking to a monkey.

But Yuina just glared at me with annoyed eyes and grumbled.

“Ehh… I miss Hotaka’s dick.”

“Don’t say that kind of stuff in the house!”

What the hell is wrong with her!?

I stood up and tried to push her out of my room.

“Hey, don’t pull me!”

“Then just get out already.”

“Fine, fine. Jeez.”

She gave in and stood up, turning her back to me.

Right before leaving, she looked back and stuck out her tongue.

“I’m not giving up, okay?”

With that, she finally left my room.

Who knows what kind of temptations lie ahead…

Yuina’s lingering scent still hung in the air.

Thanks to that, I spent a restless, sleepless night.

Hello ebyone, Shinigami-san here with new noberu: ecchi and imouto! well step so it’s okay. (Yuki would disagree….)