The Protagonist's Sister Loves Me, But She's Definitely a Yandere. - Chapter 29: Tension

Chapter 29: Tension

The stalker’s hostility toward Mimi was getting worse.

They were now sneaking photos taken in secret and even bugs into Mimi’s shoe locker. It was clear harassment.

This was getting beyond something we could handle on our own. I started to think it might be time to get teachers or parents involved.

But I couldn’t make that decision alone. I had to ask Runa and Mimi how they felt. There were two reasons for this.

First, if adults got involved, it would turn into a big deal. In other words, we’d be drawing a lot of unwanted attention.

If people found out that Mimi and Runa were part of this, gossip-hungry students would twist the story and spread rumors for sure.

And the worst part? The stalker might lash out even more at me or Mimi.

Ideally, getting adults involved would make the stalker back off. But if it made them more resentful instead, things could get really dangerous.

Plus, we still didn’t know who the stalker was. If teachers or parents stepped in, it would turn into a major investigation.

We already had more than enough evidence: threatening letters, hidden photos, and bugs.

This uncertainty about what the stalker might do was the first reason I hesitated.

The second reason was our work as event committee members.

Right now, we were busy preparing for the sports festival. If we involved adults, there was a real chance our work could be put on hold.

Letting students carry on with something this dangerous wasn’t just risky –it was downright irresponsible. If you thought about it logically, our roles as committee members would probably get restricted.

Mimi hadn’t shared all the details, but I could tell she cared a lot about the sports festival.

I didn’t want to ruin that for her.

She probably dreamed of being on the committee with Hinata and was hoping that this big event would help her take a step forward in their relationship.

Because of all this, I decided not to take action on my own. I’d ask Mimi and Runa what they wanted to do.

…But there was something else that kept bothering me.

Why hadn’t the stalker targeted Runa?

Logically, Runa was the closest to me. If someone was going to lash out, it would make sense for her to be the target. But that hadn’t happened. And that bugged me.

Could the stalker actually be Runa?

If I wasn’t just full of myself, I knew Runa genuinely cared about me.

But even then, I couldn’t imagine her going so far as to stalk me.

Besides, she lived right next door. She knew everything I did without needing to stalk me. It just didn’t make sense.

Honestly, when I thought about it, I just didn’t want to believe it.

I couldn’t stand the idea that Runa Ichinose was behind this, that she was the one tormenting Mimi. I kept hoping it was someone else entirely.

At this point, all the evidence and circumstances made Runa seem like the most suspicious person.

I couldn’t forget about that handkerchief either. I kept telling myself I’d ask her about it someday, but that day never seemed to come.

“…That’s an unexpected pair.”

It was probably just a coincidence.

I was carrying a box of documents. A teacher asked me to help since it would be tough for the girls to do it. My thoughts were all over the place as I walked through the school building.

Up ahead, at the landing of the staircase.

The sunlight streaming through the window was a reminder of how long the days had gotten. Two girls were standing there in the light. I stopped in my tracks, surprised by the unexpected pairing.

“Ogawa and… Kusunoki… the older sister?”

Bright blonde hair and long black hair.

At a glance, with no one else around, it almost looked like a delinquent girl shaking down a quiet student for money.

But in reality, it was the feisty hamster and the mastermind behind the mistaken love letter.

At first, I thought it might be Kusunoki’s younger sister, but the long black hair was a giveaway. It was definitely the older sister.

Still… what was this about?

From an event committee perspective, it wasn’t that strange to see them together. But Kusunoki-senpai was part of the student council, not the event committee. Their roles didn’t overlap that much.

I wondered if they were friends, but I’d never seen them chatting casually before.

The two of them weren’t carrying anything. There was no sign they were doing any work.

But neither of them seemed like the type to slack off. That only made more questions pop into my head.

“It’s up to you, Kusunoki-senpai, whether to make use of it or destroy it.”

“…Yeah, thanks.”

Mimi and Kisa Kusunoki were talking seriously. It was just a coincidence, but I ended up eavesdropping.

I didn’t mean to listen in, so I decided to leave. But my feet wouldn’t move.

I froze in place.

“And we agreed not to talk about this at school, remember? What if someone hears us? You know what the goal is, right?”

“Ah, sorry… I just got nervous…”

“…Well, good luck.”

That agreement sounded suspicious.

It was now clear that Mimi and Kusunoki-senpai knew each other. But it seemed like they had agreed to avoid interacting at school.

I caught the end of their conversation, so I didn’t fully understand what they were talking about.

But it didn’t feel good.

“It sounds simple to me.”

“That’s because it’s you, Ogawa-san…”

“Believe in yourself. Tell yourself you can be anything, do anything. Just keep pushing forward.”

It seemed like their conversation had really ended. The sound of footsteps coming closer echoed off the hallway walls. I quickly hid in a blind spot and waited for them to pass.

I didn’t even know why I hid.

I just happened to be there by coincidence. There was nothing wrong with that.

“Ogawa-san. Aren’t you scared?”

Kusunoki-senpai called out to Mimi as she walked away.

I didn’t know what exactly she meant, but Mimi’s laugh echoed in my ears.

“Of course I’m scared.”

“…I’d be terrified. If I were in your shoes, I think I’d be crushed by the pressure.”

“You’re too soft, Kusunoki-senpai.”

Mimi continued.

“There’s no other choice but to keep going.”

The box I was holding felt damp from the sweat in my palms. It wasn’t just from exhaustion —it was from tension.

(…Ogawa and Kusunoki-senpai.)

Eventually, Mimi’s footsteps faded, and Kusunoki-senpai hurried away as well.

(…I need to find out the truth.)

Maybe it was lucky I had been there. But it didn’t feel like luck.

I pushed away the thoughts that crept into my mind.

Thoughts I had ignored —or rather, thoughts I hadn’t even considered— were now standing right in front of me.

I needed to confirm this tomorrow.

I wouldn’t tell Runa. This was something I needed to handle on my own. I couldn’t shake the thought that Runa might be involved somehow.

A new possibility had come up.

Who was the stalker? Who was targeting me? And yet… I still couldn’t figure out why Runa wasn’t being targeted.

“…Man, this is exhausting.”

I muttered with a cracked voice.

The words barely formed and faded into the air, disappearing without a trace.