While Taking Care of My Shut-In Little Sister, I Somehow Ended Up Ejaculating Inside a Beautiful Girl

Chapter 10: While on a Date with a Beautiful Girl, We Somehow Crossed a Line

Back home, I stood in front of my sister’s locked door, holding a tray of dinner I’d prepared, and called out through the wood.

“I’ll probably be out all day tomorrow. I’ll make breakfast, so handle lunch yourself. I might be late for dinner too, so eat something if you’re hungry… Sound okay?”

No response, as usual. But I had a vague feeling she was listening. Just a hunch, really.

“Dinner’s here.”

I set the tray on the floor and turned away.

All I can do for my sister is take care of her while I’m home.

Sounds like a tautology, but it’s the truth, so what can you do?

Tomorrow, I’ll be out with Yuu almost all day.

Leaving the house for a whole day—am I allowed to do that?

I don’t have the answer.

For safety’s sake, even leaving during the day is a risk, but if I followed that logic, I couldn’t go to school.

While I’m at school, living my “school life,” my sister manages her “daily routine” (staying holed up) without issue.

So, going to school and running errands like grocery shopping—those delays count as part of my “daily routine” and “school life.”

Specifically, my “free time” to be away from home is about twelve hours, from 8 a.m. to 8 p.m.

But that’s only on weekdays.

On days off, this “free time” tends to shrink because school’s out.

Our parents come home occasionally, but only for a few days—sometimes just one or two. The gaps between their visits are usually at least a month, often longer.

With parents absent and my sister shut in, that’s our reality for long stretches.

In that state, unless something else takes priority, my top goal is protecting my sister and the house.

“School.”

“Errands.”

Those are my current “excuses” to step away from home duty.

Without those excuses, I’m responsible for our safety.

No late-night karaoke. No inviting friends over, even guys.

Since middle school, and even now in high school, I’ve done what I can to keep things safe, but how long can this go on?

Can I keep it up?

If only we had an auto-locking door like Usotsuki-chan’s place, I’d feel a bit better about going out—but no luck.

Resources are finite, and a house, once built, doesn’t change without major renovations.

I’m a minor, not a carpenter. If I can’t change the house, I have to change my life.

This lifestyle’s actually pretty restrictive.

“Emancipation by marriage… not exactly realistic.”

Legally, a married minor is treated as an adult—emancipated.

It comes with obligations but opens up more possibilities.

If I could use that—say, enter a paper marriage with someone—it might ease things…

“No way. It wouldn’t change my sister’s situation. Unless she chooses to leave her room, it’s pointless. Special measures would just add financial, time, and effort burdens—dead weight.”

Only a few could benefit from such measures. Adoption’s out for similar reasons, plus our parents would likely never agree.

“…What happens to this house when I graduate high school?”

I pondered vaguely.

Some relatives have vanished. Others passed us around like a hot potato.

No one’s there to care for us, so this is our life now.

Blood’s thinner than water.

“Even relying on someone close…”

The Onoderas next door?

They’d help if I asked, no doubt.

Even if it meant sacrificing themselves.

Yuu’s already going out of her way to help with my life—mostly food-related stuff—and I’m grateful.

But I’ve decided not to use her.

Or her family.

There’s no point.

—No, “use” isn’t the right word.

In this situation, borrowing their help would be “utilizing” them, but not in the sense of fully leveraging their strengths. Point is, I’ve decided not to “use” or “rely on” Yuu or her family.

The biggest reason, though, is emotional.

Yuu’s by my side, and I’ve got nothing to offer her in return.

I want to give her something back, but I just end up leaning on her.

Is that happiness for her?

She’d probably say it is.

But that’s likely temporary.

Someday, it might pull the trigger on my own self-destruction.

Showing her that moment would surely make her unhappy.

“…What’s gonna happen from here?”

My shut-in sister?

Our busy, absent parents?

My future?

My sister’s future?

I don’t know.

I don’t know anything.

My future’s always been a torn-up blank page.

…No, let’s not be so negative.

Think positive. Positive.

Yeah, let’s say—

My unseen future’s a blank page, brimming with possibilities.

Optimistically—

Think about fun things—

I snapped back to reality in the first-floor living room. I’d been zoning out.

My stomach growled.

“Come to think of it, I haven’t eaten. Guess I’ll make dinner—”

As usual, I forgot to prep my own meal. The image of a seafood-flavored instant noodle cup, part of our overstocked pantry, flashed in my mind.

“…Nah, pass.”

I’m so done with those.

Sorry, I’m begging for forgiveness. There’s no way I can finish that stock before it expires.

Absolutely no way.

“Screw it, I’ll study.”

Resigned, I opened my schoolbag and spread out my study materials. Pens, textbooks, notebooks, and reference books took up over half the table, no matter how compactly I arranged them.

“…”

I studied silently, finishing two subjects for the upcoming test, then closed the book.

The clock read around 11 p.m. About two and a half hours had passed.

“Man, I’m beat.”

Exhausted, but…

“…Not sleepy.”

I should be tired.

I should be sleepy, but I probably won’t sleep in this state.

I just know.

My body’s memorized this feeling—countless sleepless nights, plagued by insomnia.

It’s weird, being sleepy but unable to sleep. In a bad way.

Lowered focus, more zoning out, tanking efficiency—all from sleep deprivation, yet I can’t sleep. Zoning out during low-efficiency tasks makes it worse, a vicious cycle.

“…Probably ‘cause I overthought earlier.”

That’s gotta be it this time.

“…”

Feeling like nothing mattered, I left my study stuff out and went to take a shower.

I opened my eyes, and the darkness had become familiar enough that I could faintly make out the outlines of objects. I could feel that a long time had passed without sleep.

After my bath, I’d collapsed onto the sofa, closed my eyes, and… how many minutes had gone by?

I grabbed the remote and turned on the living room’s ceiling light’s dim bulb. The clock in the darkness told me only about ten minutes had passed.

…What? No way…?

The faint hope I’d held before lying down was crushed in an instant.

Hardly any time had passed.

I’d tried not to think too much, but I still couldn’t sleep.

My mind wasn’t resting.

My body, though, felt like it was recovering, the physical fatigue slowly easing.

“…Damn it.”

Lately, spending time with Yuu had mysteriously improved my sleep quality—a small miracle.

But it was just that: a miracle.

Without the blessing of that angelic girl, Yuu, I couldn’t even sleep properly.

It’s like I was starting to depend on her—

“…!”

Me, depending on Yuu…?

Using her… leaning on her…?

For me, that was an utterly unacceptable reality, a chill running down my spine. It crossed the “minimum” line I’d drawn for myself—the absolute worst thing I could do.

Using her kindness, her goodwill—that was the lowest of the low.

“Me…”

This isn’t good.

Sleep deprivation isn’t good.

“I… yeah, that’s it, I need to sleep in my bed…”

Right. My brain must be so foggy it’s mistaking the sofa for a bed.

If I’m subconsciously craving sleep, then come on, sleep, just hit me already.

I dragged myself up from the sofa, my legs wobbly, and headed upstairs.

I nearly tripped a few times climbing the stairs.

My vision was swaying.

Finally, I reached the top—and then it happened.

Creak…

“—!”

A sound, like the floor creaking, came from the hallway or one of the rooms.

“…What?”

Did my sister come out of her room?

No, that couldn’t be.

It was too faint a hope, one I knew would be betrayed. No way.

As expected, the door to her room at the end of the hall was firmly shut.

And thinking about it, there’s no way a creak from her room would carry all the way to the stairs.

“Is someone there…?”

No shadows in the hallway.

But the sound couldn’t have come from too far away.

The idea that climbing the stairs could make the hallway floor creak halfway down? That’s absurd. This isn’t some decades-old wooden house.

“…”

I looked at the nearest door—my own room.

“Anyone there?”

No response to my call, of course.

“…”

I stood in front of my room.

Without hesitation, I opened the door—

“Who’s there?”

No answer.

In the pitch-black room, my darkness-adjusted eyes caught the outlines of my desk, chair, and bed.

No open windows.

No suspicious figures.

“…Am I being paranoid?”

Tomorrow, I’ll be out longer than usual for my date with Yuu.

Maybe I’m subconsciously scared, too on edge about leaving the house.

If an intruder got in and harmed my sister—I’d never forgive myself.

If only I’d been home.

If only I’d been there for her.

“…Well, as long as it’s not an intruder, I guess it’s fine…”

I let out a sigh of genuine relief, stepped into my room, and flipped on the light.

“…Oh.”

But then, something strange happened.

The moment I entered the room and turned on the light, an overwhelming wave of sleepiness hit me. I couldn’t sleep in the dark, but now?

“…Weird, I feel… calm…”

Strange.

What was this sensation, like being wrapped in something soft?

I turned off the light I’d just switched on.

The heavy sleepiness stayed, and I stumbled to my bed, diving in.

It was later than usual, but for some reason, I felt like I’d sleep deeply.

It was like being enveloped in something soft, a comforting warmth, and I let myself relax into it.

My consciousness dulled rapidly, sinking into the depths of sleep.

“(Ren-chan…♥ Ha…♥ Ha…♥ Ren-chan…♥ …Ngh, mm…♥ Hah—mmph…♥)”

A feverish voice whispered close by, panting. Warm breath brushed my neck.

Sniffing, smelling me, rubbing her inner thighs together—it was Yuu.

My childhood friend, my neighbor, my fake girlfriend, the popular high school honor student.

Her long black hair, usually tied in a braid, was loose and disheveled, her sleepwear slipping off—seductive, alluring, almost bewitching.

She was doing perverse things to my unconscious self.

Knowing her, this behavior seemed impossible.

—Oh, a lucid dream.

A dream where you’re aware you’re dreaming.

That’s exactly what this was.

I’m dreaming right now.

The setting is my room.

In the darkness, Yuu is in bed with me, breathing heavily, clinging to my body.

Her arms and legs wrapped around me, like an octopus or squid ensnaring prey, she hugged me tightly, rubbing her crotch against my thigh, sniffing my neck.

The parts of her pressed against me were hot.

The heat trapped under the blankets had nowhere to go.

My skin was slightly sweaty, and hers was the same—or more.

The soft, marshmallow-like feel of her chest against my arm.

Each time her crotch rubbed against my thigh, the heat was more than just friction, a damp warmth spreading.

Her body was undeniably feverish.

Her post-bath scent reached my nose. And probably, surely, my scent was reaching her.

—But.

Despite the situation, it wasn’t uncomfortable at all. That was the strange part.

In the dream, I instinctively realized it.

A terrifying fact. A shocking truth.

This was the essence of restful sleep.