Decisive Friday.

The fourth period on the fateful Friday.

Ishida and I were on pins and needles.

Today was the day Kazumi-san might be going to see her boyfriend.

“Times like this, being a science major seriously sucks. Our schedule has zero flexibility. We can’t keep up with the movements of a humanities department.”

Ishida must have been feeling the exact same way.

He let out a frustrated murmur.

“You’re right. Especially since the only people who know about this situation are you, me, and Toko-san—and all of us are in the science and engineering department.”

“Honestly, it would be perfect if someone like Mina-san, who’s in the same economics department as Kazumi-san, could be in on the plan… but we can’t really do that.”

“Yeah, given the nature of the situation. It’s not something you can easily tell others. Besides, Kazumi-san wouldn’t want people to find out about it either.”

Just as we finished saying that, my smartphone vibrated.

I checked it and saw a message from Toko-san.

Toko: Yuu-kun, your class is about to end soon, right? Can you come out as soon as it’s over?

I immediately typed a reply.

Yuu: Yes, about 20 minutes left. Did something happen?

Toko: It looks like Kazumi really is going to see her boyfriend today after all.

Yuu: Are you absolutely certain?

Toko: Yes, because Kazumi just headed toward the Marunouchi Line.

Yuu: Are you following her right now, Toko-san?

Toko: Yes. At lunchtime, Mina told me that Kazumi had withdrawn a huge sum of cash today.

Yuu: Is that money meant for her boyfriend?

Toko: Most likely, yes. That’s why I skipped my fourth-period class to keep an eye on Kazumi’s movements.

Yuu: Understood. We’ll head over immediately too.

Toko: You guys can wait until your class is finished. Ah, she definitely boarded an inbound train. Talk to you later.

“Did something happen, Yuu?”

Noticing my tense demeanor, Ishida questioned me.

“It looks like Kazumi-san is on her way to see her boyfriend. She apparently left campus and boarded the Marunouchi Line.”

“The Marunouchi Line? Is she heading to that apartment she leases in Nakano?”

“Most likely.”

“Damn it! We need to leave right now!”

“Hold on, there’s no way we can break out of class right now. There’s only about 15 minutes left. We have no choice but to wait it out.”

“But in the meantime…”

“Toko-san is tailing her for us right now. We have to wait for her updates. We don’t even know which apartment in Nakano it is.”

With those words, I managed to calm Ishida down just as he was about to bolt out the door.

The moment class ended, we dashed out of the classroom and sprinted toward the station.

I fired off a message to Toko-san while we were on the move.

Yuu: We just left campus. Where are you right now, Toko-san?

Toko: I just stepped out of Honancho Station. I’m currently tailing Kazumi from behind.

Yuu: Got it. Honancho, then.

Toko: Yes. The main avenue leading straight from Honancho toward Shinjuku. I’ll message you again once I pin down the apartment.

Yuu: Understood. If possible, please share your live location. Also, even if a conflict breaks out, please don’t intervene by yourself, Toko-san. Wait until we arrive.

I was terrified that if Kazumi-san and her boyfriend got into a physical altercation, Toko-san might step in to break it up and end up getting hurt.

Toko: I understand. Hurry over.

“Did she find the apartment?” Ishida asked impatiently.

“Yeah, she said Kazumi-san got off at Honancho. She’s heading toward Shinjuku from there. Toko-san will contact us again as soon as she pins down the exact apartment.”

“Honancho, huh. From here, it’s about a 20-minute train ride.”

“Anyway, let’s move fast. I just hope nothing terrible happens over there.”

Nodding to each other, Ishida and I sprinted onto the Marunouchi Line platform.

By the time we arrived at Honancho Station, a new message from Toko-san had landed.

It was the address of Kazumi-san’s apartment.

Checking Google Maps, it was located slightly south of the main avenue heading toward Shinjuku.

In terms of distance, walking from Nakano-fujimicho Station might have been roughly the same.

We bolted toward the location as fast as our legs could carry us.

The apartment building stood tucked away inside a residential area.

The neighborhood was a chaotic mix of old and new housing.

While there were plenty of beautifully built modern homes, you could catch glimpses of weathered houses scattered around that looked like they had been standing since the Showa era.

And right in the middle of it all stood a classic, old-fashioned apartment complex.

Two structures stood side-by-side, with an open, dirt-lot outdoor parking space right next to them.

Toko-san was waiting for us there.

“Toko-san!”

As we rushed up to her, she pointed up toward the room at the very end of the second-floor balcony.

“Kazumi went into that room over there.”

Being a traditional, old-style apartment building, it was the type where an outdoor staircase led directly to each front door.

“How did Kazumi-san look?” Ishida asked, anxiety etched deep into his face.

“Mina contacted me at noon saying, ‘Kazumi withdrew nearly 100,000 yen. I wonder if she’s going shopping?’ I got worried and trailed her from the moment she left school… but seeing that she came straight to this apartment, she must be handing that money over to her boyfriend…”

“Has anything unusual happened since she went inside the room?”

“Nothing so far. But…”

Right at that moment, the violent sound of something smashing, followed by a man’s enraged shouting, echoed from the apartment.

The three of us locked eyes instantly.

“Let’s go!” I barked.

Without a word, both of them gave a sharp nod.