MBSGM 03

Chapter 03 

 My Stepsister’s Delusions Are Way Too Extreme

“Huh…!? What the hell are you saying!?”

I reacted instinctively to Yui’s outrageous words, and she, still with a smirk tugging at the corners of her mouth, replied:

“Am I saying something strange? I mean, it feels wrong for a high schooler to do naughty things with a middle schooler, but if it’s two high schoolers then it’s fine… O-or wait, don’t tell me, could it be that my big brother actually does want to do those things with me while I’m still in middle school!? Ohh, I never even considered that line! But, you know, if you think about it from the angle of forbidden love, maybe it adds another layer of thrill—”

Her imagination was starting to spiral completely out of control, so I quickly cut her off.

“That’s not what I said, and it’s not what I’m thinking, so don’t even consider that possibility! What I mean is—forget about age or anything else—there’s no way I’d ever do something like that with you, Yui.”

“No way you would…? And how can you say that so confidently?”

It felt absurd to have to even explain something so obvious, but as her older brother I had to make sure she understood clearly.

“Because we’re siblings. Brothers and sisters aren’t supposed to do those kinds of things.”

“If we were blood-related, then maybe your reasoning would make sense. But we’re only step siblings, so it doesn’t apply. Right now, in front of you is just one girl. And in front of me, there’s just one boy… That’s all there is to it, isn’t it?”

“We’re still family. It’s not a relationship you can dismiss so easily.”

“If you and I got married, the form of family we are would simply change—from familial love into romantic love. Is that really such a problem?”

Yui said this with a look that suggested she truly didn’t understand my perspective at all.

…When she first mentioned wanting to marry me, I hadn’t expected it to go this far. But at least one thing was now clear—Yui was serious about wanting to marry me. She felt no shame about it whatsoever; in fact, she seemed incredibly proactive about it.

…For now, I decided to be satisfied with the fact that I had at least gotten a clearer picture of her true intentions today.

“If we keep talking about this, it’s going to drag on forever. Let’s leave it for another time.”

“Got it! Spending this time eating with you is precious too, so I’ll listen to what you say!!”

She flashed me a bright smile as she said that. …Honestly, if she could just remain as a normal little sister, she’d really be the perfect one for me.

After that, we finished our dinner together, then I took a bath and decided to head straight to bed.

Tomorrow, I’ll tell Shizuku about what happened and think up a plan together—

And then, the next morning, at school.

As I took my seat in class, Shizuku, who sat right in front of me, turned her chair around and faced me.

“Morning. Did you figure anything out about Yui?”

“Morning… Yeah, I think I managed to understand most of what Yui’s been thinking.”

I explained to her—leaving out some details—what Yui and I had talked about the day before.

After listening, Shizuku nodded and said:

“I see… So basically, when Yui said she wanted to marry you, she meant it literally. Since you’re not blood-related, she thinks that’s a valid excuse and genuinely wants to marry you.”

“Yeah. That’s why today, I want us to talk about how I can change the way she thinks.”

“Alright… But I think it’ll be difficult to change her entire mindset all at once. So first, you need to approach it indirectly.”

“Indirectly…?”

“Mm-hm. Right now, I think Yui only sees you—the closest boy in her life. So you need to show her that there are plenty of other guys out there in this world. You might think that’s obvious, but sometimes the obvious needs to be spelled out… and as her brother, it’s your responsibility to do that.”

…Given Yui’s unusual upbringing, that might actually be true. Maybe it really is my job to teach her those things.

“Alright. I’ll try telling her when I get home today.”

“Good… Hey, Kazu, after school today—”

Shizuku started to say something, but then stopped herself.

“Shizuku?”

When I called her name, she gave me a small smile.

“No, never mind… You’re busy enough with Yui right now. Really, it’s nothing.”

“I see… if you say so.”

…For a moment, her expression seemed a little awkward. But if she didn’t want to say more, then I figured I shouldn’t press her.

After school, I immediately headed home.

And when I got there, Yui greeted me at the door with a big smile.

“Welcome home, big brother! So, right away… wanna take a bath together today?”