The Protagonist's Sister Loves Me, But She's Definitely a Yandere. - Chapter 20: The Scent of the Rainy Season

Act 2: Sports Festival

Chapter 20: The Scent of the Rainy Season

By the time June arrived, the feeling of spring was long gone, and the school seemed to carry a relaxed vibe.

The weather screamed “rainy season,” with dark clouds looming in the sky. 

Raindrops pattered endlessly against the windows. Since I associate humidity with discomfort, I genuinely dreaded this season.

My returned test papers had no red marks. In other words, freedom was secured. No extra classes, no big dents in my grades. 

Most importantly, no one could say, “And he’s supposed to be Hinata’s childhood friend?”

“Shinji~, let’s go to the gym!”

A lazy-sounding voice. I looked up to see Hinata standing there with his usual handsome face. 

Somehow, even his gym clothes seemed to glow —the power of being Hinata, I guess. Since today’s class was co-ed, both the guys and girls seemed a little more excited than usual.

Hinata, naturally good at sports, was clearly looking forward to gym class.

“Yeah, we’re doing basketball, right?”

“Yep! Man, my ball control’s gonna be on fire today!”

“…What the heck does that even mean?”

Ignoring Hinata’s random chatter, the two of us walked side by side toward the gym.

Several days had passed since the date.

Runa had been acting completely normal since the exams ended. Today, like any other day, she handed me a lunch box right as we were leaving for school. Everything felt so routine that I didn’t even know how to bring it up.

Are you the stalker?

There was no way I could ask that.

The handkerchief I glimpsed that day was definitely one of mine. I’d lost it a while ago. It wasn’t anything special —just a cheap one— so I hadn’t given it much thought when it went missing.

(…When did I even lose it?)

“Shinji. Looks like we’re paired with some first-year girls. And guess what? They’re from Runa’s class… Ugh, I wish I could skip gym just this once.”

“We’ll probably be on separate courts, so who cares?”

“That’s easy for you to say. She actually likes you. Look at how she treats me —it’s like night and day.”

That’s probably because of your own actions, I silently retorted.

Hinata kept whining, his self-inflicted problems flying past me as I half-listened.

The real question was:

Did I lose that handkerchief by accident?

Or did Runa take it?

“She makes you lunch too, right? So… are you two dating?”

“No way. Stop jumping to conclusions, idiot.”

“Man, you’re so cold, Shinji. …Well, if you do end up dating her, let me know. I’ll congratulate you. Honestly, you’re probably the only one who can handle my demanding, stubborn sister. I’m counting on you.”

I knew full well that she wasn’t the kind of person who’d steal.

It just didn’t seem possible. But still…

Some things lined up a little too well. I’ve always been prone to losing things. I just assumed it was part of who I am. But if it was intentional —if Runa harbored some kind of twisted resentment or obsession toward me— it could explain a lot.

Yet, it was hard to believe she was the stalker behind everything. There wasn’t enough evidence, and a lot of things didn’t add up.

First, there was the handkerchief.

Runa was meticulous. It was entirely possible she had different handkerchiefs for different uses —one for makeup touch-ups and one for regular use. Maybe she happened to have the same silly dog print by chance. It was a stretch, but not impossible.

The issue was, I couldn’t remember exactly when I lost that handkerchief. And I wasn’t sure if it was still being sold anywhere. When I did a quick search, I couldn’t find it. From what I recalled, that handkerchief had been a random gift from one of my parents. So how did Runa end up with it?

That was where the connection to the stalker came in.

But like I said, there wasn’t enough evidence. A handkerchief alone wasn’t enough to accuse her of being the stalker. It just didn’t hold up.

(…There’s one more thing.)

Let’s say —just hypothetically— that Runa is my stalker.

Then who was the girl I chased that night?

The memory was still vivid: the chase through the dark streets, the adrenaline, the frustration.

It happened right after I saw Runa home. 

She had gone inside, and then she was standing in front of my house. There’s no way she could’ve teleported or anything ridiculous like that.

So, if that’s true, then the girl I chased wasn’t Runa.

As long as that person exists, I can’t just conclude that Runa is the stalker.

Still, I needed to figure out the truth behind that handkerchief.

…And if possible, I’d really like to know what happened to the missing underwear, too.

“Alright! Let’s go wild!”

We reached the gym, and before the teacher could even give instructions, Hinata ran onto the court, already hyped up. A bunch of energetic students naturally gathered around him, and a mini-game kicked off, boys and girls alike joining in.

I stood there, quietly watching.

It had been a while since the stalker situation started. The creepy letter, the weird threats, the constant surveillance emails —the mystery still hadn’t unraveled. I didn’t even have a clue who was behind it. The frustration was eating at me.

Then, something occurred to me.

(…The timing of the emails…?)

The stalker had been watching me. An email arrived when I was with Mimi.

But when it came to spending time with a girl, I was with Runa way more often. Especially since she’d come up with that plan to provoke the stalker with jealousy. She had been sticking around me even more since the start of the week.

Yet no emails came during that time. Why not? Could it really mean Runa was the stalker? No, I’d just decided that was too hasty a conclusion.

Could there be a reason the stalker didn’t send emails when Runa was around?

“Sigh…”

I sighed, feeling the frustration build. Then I felt a light tap on my back. Turning around, I saw Runa giving me a puzzled look. The sight made me feel an awkward guilt for no good reason.

She looked me over and said,

“Shin-nii, you’re going to lose all your luck if you keep sighing like that.”

“I’m just tired. From… everything.”

I tried my best to act normal.

In her gym clothes, Runa’s figure stood out even more. Her long limbs, that flawless, pale skin. The memory of holding her hand at the movies crossed my mind. I wondered what she thought about that now.

“So, what? Did something happen with your stalker case?”

“…No, not exactly. And hey, don’t just throw around the word ‘stalker’ so casually.”

“No one’s paying attention. Look at that bunch —he’s getting all the focus.”

I felt like pointing out, “The stalker is probably listening in.”

That said, sneaking into gym class would be hard. If the stalker was a student, they’d have their own classes to attend. Skipping would need a good excuse. If they happened to have gym right now, they’d be stuck.

“Looks like things are heating up over there, with Hinata at the center of it all.”

“It’s just annoying. To me, it’s like a circus act.”

“If someone overheard that, Hinata’s fans would lose their minds.”

Runa just shrugged and chuckled softly. She seemed like she didn’t care who listened. But she always knew how to handle things. People around us thought she and Hinata were just bickering siblings.

In reality, it was more like they were stabbing each other with verbal knives.

But maybe because she was Hinata’s sister, people didn’t make a fuss about how close she and I were. The gym echoed with endless cheers for Hinata —the general consensus seemed clear.

“Hii-kun! You got this!!”

That was Rika’s voice, loud and unmistakable.

“Oops, I’m late— Wait, what?! Hinata-senpai looks way too cool right now!”

A squeaky hamster-like voice rang out from the gym entrance.

I shot Runa a questioning look, and she muttered, “She’s in my class.”

Ah, that made sense. They were both first-years, after all.

“Oh, Usui-senpai, you’re here. …And, uh, Ichinose-san, hi.”

Mimi gave me a casual nod and flashed Runa an awkward smile.

Just to clarify, there’s a definite crack between Runa and the girls in Hinata’s little harem. It all comes down to knowing the real nature of Hinata and Runa’s relationship —which was far from sibling bliss.

Runa knew what Mimi was like back in middle school. She wasn’t the type to confront people about it, but for Mimi, Runa was someone she’d rather avoid if she could.

“Well, don’t mind us. Go cheer for him already.”

“Ha, yeah… I will. See you around, Usui-senpai.”

“Yeah, later.”

I gave a small wave in response.

“She knows about the stalker, right?”

“Yeah, she found out when we were together and one of those emails came in. I was this close to catching the stalker, but that Baldy had to show up and ruin it.”

I’d already told Runa that Mimi knew about the situation. She was aware that things were getting dangerous. The plan was to pull her out the second there was any real risk, but for now, she was still helping me hunt down the stalker.

“The details were too accurate. Someone was there watching.”

“Yeah. That email described things only someone at the scene would know.”

“So if someone’s that obsessed with you, Shinji-nii…”

Runa’s expression was serious as she tried to piece everything together. Her sharp gaze and focused demeanor left no room for doubt. Looking at her like this, it was impossible to believe she could be the stalker.

But when I connected the dots with the information I had, she was always the first name that came up. The contradiction left my thoughts in a tangled mess.

Outside the gym, the rain was coming down in sheets —the start of a gloomy June.