My Little Sister Suddenly Confessed to Me, but What Am I Supposed to Do by Dating My Little Sister?

Chapter 0: Prologue

“Onii-chan…… go out with me!!”

“Huh……? What? W-why?”

I got confessed to out of the blue by my real little sister—someone I wouldn’t say I’m especially close to, but not exactly distant from either……

Maybe it’s because of global warming. In novels from a while back, they’d describe cherry blossoms in full bloom in Tokyo during the entrance ceremony.

Well, blossoms bloom at different times depending on the area, so that kind of description isn’t necessarily wrong.

My parents say that even around here, near Tokyo, there used to be fully blossomed flowers during the entrance ceremony—but these past few years, in this neighborhood, cherry blossoms are basically “graduation season,” only now, no questions asked.

Tomorrow was the entrance ceremony for the high school I’d be attending. The nearby cherry trees had already shed their petals, and thick, vivid-green leaves had grown in.

That evening, in my room on the second floor, I finished preparing for the ceremony, let out a breath, sprawled on my bed, and read my favorite book.

My everyday life—ordinary in every way except for it being the night before the entrance ceremony—was suddenly overwritten into something insane by my little sister barging in with a knock.

And as a result, the high school life that followed was about to change completely.

‘My little sister is the same age as me—except we’re not twins.’

Because I chose a high school close to home for no other reason, my younger-by-one-year sister was also going to enroll there.

Kindergarten, elementary school, middle school—we were always in the same school.

Since we were only a year apart, people kept saying, “Twins? You don’t look alike,” and the line “We’re not twins—we’re just a year apart. Of course we don’t look alike” became our standard routine at every entrance ceremony and class reshuffle. The so called toshigo – born within the same year.

My sister is way smarter than I am. When I heard she’d gotten into an academically competitive school, I felt relieved for a moment—thinking, finally, high school would be separate.

And then, right then, she casually hit me with this out of nowhere:

“Ah, Onii-chan, I’d rather go somewhere close to home too, so I’m choosing the same high school, okay~”

She said it like it was nothing.

In the end, for the exact same reason, we were entering the exact same high school, and I was honestly a little sick of it. Same school again, huh……

Anyway, quick introductions. I’m Hasemi Yuu. My little sister’s name is Shiori.

Our parents both work and are pretty busy—rarely home—but aside from that, we’re just a totally normal family.

Shiori is insanely smart. I’ve even heard she’s at a top level nationwide…… but unlike her, I’d rate myself as average—grades, looks, everything. I don’t have any particular strengths, and so far I haven’t found some hidden talent either.

Of course, I’ve never suddenly become popular like a light novel protagonist.

Confession? What’s that—does it taste good? That’s how bad it is. Ah, right—back in kindergarten, I did get Valentine’s chocolate once! See? Amazing, right………… ugh.

Anyway…… despite my averageness…

My little sister confessed to me!

I mean…… it’s my first confession ever, and it’s from my sister……

“O-okay, hold on. April Fools was last week, right? What kind of joke is this?”

“I-I wouldn’t say something like this as a joke! I’ve liked you for a long time, Onii-chan…… so………… go out with me!!”

“By ‘go out,’ you don’t mean like shopping together, right? You mean dating. Like, romance.”

“Obviously!!”

My sister stepped even closer, looking up at me as she raised her voice.

Too close. Way too close.

She smells kind of nice.

“Uhhhh—why? I mean, we’re brother and sister. Dating is……”

“I know! But—but oooooooh……!”

Her face was bright red, and as she stared at me, tears spilled out of her eyes.

At least I understood one thing: those tears were real……

“Wait. Okay, I get it, so—just wait. Don’t cry. I get that you’re serious.”

“Then you’ll go out with me!!!”

“Why me? You’re popular, aren’t you? I’m your actual brother……”

Unlike me, my sister is apparently ridiculously popular.

Long black hair that reaches her back. Big eyes, slightly upturned.

She’s small and slender—her figure isn’t exactly ‘wow,’ but paired with her baby face, she’s probably irresistible to a certain niche.

She’s cheerful and has tons of friends. Like, several times more than I have…… okay, yeah, shut up!

“Onii-chan… you don’t need a reason to fall in love…… Love isn’t something you do—it’s something you fall into.”

“Yeah, no, even if you say something that sounds nice like you heard it somewhere……”

“So go out with me!”

“What do you mean ‘so’!? Wait—dating your sibling is weird, isn’t it?”

“Is it? In recent light novels it happens all the time. And in the manga you have… it’s not just dating—there’s even crazier stuff……”

Her face somehow got even redder as she rambled on.

“Wait. My manga—what have you been looking attttt?!”

I grabbed her shoulders and shouted.

“What do you mean ‘what’? The ones under the bed mattress.”

She answered calmly without even flinching at how close my face was. No—this is not the issue here!

“YOU DIDN’T HAVE TO SAY THAAAAAT! And that’s fiction. Not real life!

Also, if you’re looking for something, give up on the ‘under the bed’ cliché. And don’t come into my room without permission! And don’t go snooping!”

“Ehhh, but online too, people say they’re dating their siblings and stuff…”

“I don’t even know where to start correcting you. Fine—okay—just stop. You don’t need to say any more……”

My head started to hurt, and I managed to respond while pressing my fingers to my temple.

“So… will you go out with me?”

She stared at me with serious eyes, filled with tears.

I don’t dislike her. Honestly, I even think she’s cute—but that’s only as my little sister.

Still… I’d never seen her with an expression this desperate before……

And since it was the first confession I’d ever gotten, I couldn’t even imagine a way to reject her without hurting her……

“Let me think.”

I ended up choosing an answer like some spineless light novel protagonist.

What do I do…… for now, I guess I need to change where I hide my porn mags……

Name: Hasemi Shiori
Bust: A secret from everyone except Onii-chan
Waist: I’ll tell only Onii-chan
Hips: I’ll have Onii-chan measure them for me
Likes: What Onii-chan likes
Dislikes: What Onii-chan dislikes
Hobbies: Exploring Onii-chan’s room; writing an Onii-chan picture diary
Special skills: Knowing everything about Onii-chan; making coffee for Onii-chan