Chapter 43: The Sister’s Self-Destruction

The Sister’s Self-Destruction

In the dimly lit room, I watched Yuna, her lips curled into a faint smile.

A sense of disgust I had never felt before welled up inside me.

Ignoring her would probably be the wisest choice.

But leaving this woman unchecked was far too dangerous. There was no telling what she might do.

That’s why I had never blocked her messages or cut off contact completely.

I kept a connection—just enough to keep an eye on her.

So that if she made a move, I could be the first to act.

But this time, I had completely miscalculated.

It had never even crossed my mind that that man might be under Yuna’s influence as well.

We had met through a friend’s introduction, so I hadn’t thought to consider any ties to her.

“So, you’re going to tell me about Akemichi Kazuma-kun, right?”

“Yeah. Actually, he’s my cousin. Crazy coincidence, huh? When Kazu-nii mentioned your name, Mizuki-san, I was stunned.”

From the way she spoke, it seemed like Yuna hadn’t been involved in how we met, and I felt a small sense of relief.

“Then why did you try to set me up with your cousin?”

“Oh, Kazu-nii asked me for advice. Apparently, it was love at first sight. Since I happened to know you, I just gave him a few pointers. That’s all.”

She had grown more cunning since the last time we met, offering only roundabout, inoffensive answers.

“I see. You even went as far as taking a picture—how thorough of you. I’ll admit, letting you take that shot was my own carelessness. But sending it to Yuki? That, I can’t forgive.”

Yes. What I couldn’t forgive was that she had dragged Yuki into this.

At my words, Yuna’s lips curved into a satisfied, almost affectionate smile before she declared—

“That was for Yuki’s sake, too.”

I could only scoff in disbelief.

Yuna had always gone on about “protecting” Yuki and doing things “for his sake”—but in the end, all she had done was make him anxious.

“Did it never occur to you that this might hurt Yuki?”

“Of course, I considered that. But for Yuki, Mizuki-san is still his sister. Unlike with me, I knew he wouldn’t sever ties completely. In a way, that’s precisely why I understand Yuki better than anyone.”

Her smug tone sent a sharp irritation through me.

It was as if she was claiming to know Yuki better than I did.

“Oh, but thanks to you, this time was different. Yuki actually listened to me. More than that—he believed in me.”

Maybe that’s why I couldn’t help but mock her, comparing her situation to mine.

“I see… So in the end, family really does mean a lot to Yuki. But, just as I expected, everything played out exactly as I had foreseen. A little ahead of schedule, though.”

Her face clouded for a moment before she quickly recovered, flashing me a victorious smile.

Normally, I would have brushed her off without a second thought. But right now, I wasn’t thinking clearly.

The ugly side of me reared its head. I shouldn’t have to compete, yet I found myself wanting to prove that I was the one truly suited for Yuki.

“In a way, I have you to thank… truly. If not for you, Yuki and I might never have crossed that final line of our own free will…”

The moment those words left my lips, Yuna’s expression changed. She looked at me as if I were something incomprehensible, something she couldn’t believe existed.

A small part of me felt satisfied at her reaction, but my mind was already screaming regret.

To keep her from pressing further, I finally said what I truly meant to say.

“…But what if, because of all this, Yuki had ended up deeply hurt? What would you have done then?”

My voice came out lower than I expected—quiet, but laced with an unmistakable weight.

In the end, everything had settled peacefully. And I was glad that Yuki had worried about me. But if things had taken even a single wrong step, he could have been hurt beyond repair.

Yuna stared at my face intently, seemingly taken aback.

“W-Well… when that time comes, I just want to be there for Yuki… to stay by his side and heal him, truly… this time for real.”

“Hah, so you were just trying to position yourself next to Yuki, weren’t you? What happened to what you said before? You told me you didn’t want to go back to being lovers.”

Not that I had ever truly believed Yuna’s words in the first place.

Her logic was broken and self-serving. I knew arguing would be pointless, yet I still felt the need to say it.

“Of course, I have no intention of becoming his girlfriend. I’ll simply watch over him—closer than anyone else… Let’s see, since you’ve already taken the role of his sister, how about I take on a more motherly role instead?”

As if regaining her composure through an utterly absurd delusion, Yuna smiled innocently, without a hint of hesitation.

Meanwhile, the instant I heard those words, my anger nearly boiled over—like a kettle shrieking on the stove.

This woman… she had no idea what she was saying.

I clenched my fists, summoning every ounce of restraint to suppress the urge to slap her.

“Do you even understand the weight of what you just said?”

My voice was eerily calm, devoid of emotion, as I met Yuna’s gaze with an ice-cold stare.

Does she truly understand just how significant that role is to Yuki?

That he became who he is now after being warped by his biological mother and then losing the stepmother who took her place… If she knows that and is still saying this—

“Ah… you’re right. ‘Mother’ might be a bit much, given the age gap. Then how about his little sister instead?”

Her response was utter nonsense.

Even if they had been childhood friends for years, at the end of the day, she was still an outsider. This only confirmed how little she truly understood Yuki—and an ugly sense of superiority swelled within me.

“I see. Then, I’ll forgive you. If you can’t even grasp something so fundamental, I’ll pretend I never heard what you just said.”

I knew full well how petty this feeling was.

There was no point in asserting dominance over Yuna, and yet, I couldn’t stop myself.

“…What do you mean by that…?”

Yuna frowned slightly, as if something in my careless remark had struck a chord.

The moment I saw that reaction, regret hit me like a wave.

My foolish need to put her down had given her an insight she never should have had.

And from the look in her eyes, it was clear my fears weren’t unfounded.

“…I see. So that’s how it is…”

She murmured under her breath, her eyes darkening with realization.

I had completely, utterly miscalculated.

Normally, no one would have pieced it together.

But this woman had been involved with Yuki longer than I had.

She had even spoken with his birth mother before.

She might not know the full details of what happened between them, but she knew enough—enough to remember that Yuki had an unusual fixation on the concept of a mother. And now, she had made the connection.

“Thank you, Mizuki-san. I understand now… what Yuki truly desires. To think you’d go out of your way to drop hints like this… You really aren’t honest with yourself.”

There wasn’t a trace of sarcasm in her voice—just pure gratitude.

That was simply the conclusion she had arrived at.

“If what you’re imagining is actually true… then what exactly do you plan to do about it?”

“Isn’t it obvious? If that’s what Yuki wants, then I want to give it to him. But… I doubt I can do that myself.”

“…You, don’t tell me…”

A horrifying thought crossed my mind. Just as she had once tried to arrange someone to satisfy Yuki’s physical needs—was she now planning to find him a “mother” as well?

“Well, I’ll think about that from here. One thing’s for sure, though—Mizuki-san, you really are my goal. The wall I need to overcome. Thanks to your hint, I’ve set my next objective. So, I’ll be heading out now.”

With that, she started gathering her things.

I had completely played myself, and I didn’t even have the energy to stop her.

Even if I tried, I’d probably just make things worse.

“Do not—under any circumstances—make Yuki remember his mother.”

My voice was firm, making sure there was no room for misinterpretation.

Yuki’s concept of a mother wasn’t some Pandora’s box with hope at the bottom.

There was nothing but ruin inside. That was precisely why it must never be opened.

“I know. Don’t worry. I do understand at least that much about what happened to Yuki.”

As his childhood friend, Yuna at least had that much awareness.

But there were deeper truths—things only those truly close to him could know.

And I could never share them with this woman.

Because of my own mistake, I had given her the key to a door that should have remained locked forever.

And then, just as she was leaving, she turned back to say—

“Oh, by the way… that scent. Did Yuki like it? It’s a new release from the line he was fond of before, so I thought I’d recommend it to you.”

I hung my head, silently vowing to never wear that perfume again.

I had utterly, completely destroyed myself.

To let off some steam, I went to sing karaoke alone for a while before trudging home in defeat.