Yamaguchi-sensei. I

May, Year 2308.

Conflict Summary:

S-Flu: 593,101,902.

Humanity: 0

Cellos Robotics Offices, District 2.

Isayama Tore, 18 years and 4 months old.

“Katy, Isayama, come with me for a moment,” Shinpei called from the office door.

Weeks after my father’s death, everything had returned to normal. Despite Tatsumi’s suspicions, the world remained unchanged. Cases emerged, infections spread, but I never heard another mention of that supposed fifth evolution my friend feared.

I was fine too. The only thing that saddened me was that my father didn’t remember me in his final moments. Even so, I remained determined to fulfill his wish, so I carried on as usual.

Giving up wasn’t an option. My goal hadn’t changed: I had to prevent more tragic endings like those of my father, Joshua Cam, or Mr. Todo…

“Coming!” Katy answered from her desk. Then she glanced over at me, still focused on my work.

I found it surprising how much a piano could change a person. Since that evening, Katy and I had grown much closer. The days when her implants made me uneasy were long behind us.

“Isayama?” Suddenly, I found myself facing those golden eyes, reflected in the lenses of my holographic control glasses.

“One second, let me just send this quote…” I worked the hologram as quickly as I could.

“I’ll wait,” she said, sitting on the edge of my desk.

“All done…” A few seconds later, I removed the glasses. Together, we headed toward the glass door. “How’s your week been?”

“Pretty good. After finishing the case with Carlos, he invited me to eat ramen,” said cheerfully.

“Huh? I thought I was his favorite apprentice…” I held the door open for Katy.

“Keep dreaming—it’s obviously me,” she teased as we stepped into the hallway, where Shinpei was waiting with a paper notebook.

Carlos… Why would you betray me like this…

“Good morning, little couple. How are you doing?”

“Little couple…” we muttered in unison.

“I wanted to talk to you both because, starting tomorrow, you’ll be working exclusively with each other,” the ex-cop announced with a smile.

“So, that’s how it is, huh?”

“I guess… huh?”

“I’m glad you’re okay with it. Starting tomorrow, you’re officially partners.”

“What?!” we shouted, again at the same time.

“Wow, that synchronization…” Shinpei commented. “It’s fitting for a pair of mates.”

“S-so soon?”

“It was my turn to be invited to ramen…” I pleaded with Shinpei.

“Relax, you two. I know you’ll do great. Oops!” He dropped the notebook, stooping to pick it up. “How awkward… Oh, I didn’t expect you so soon,” he said, addressing the figure who had appeared behind us, as silent as a ghost.

The shock nearly killed us.

“Good morning. So, you’re Shinpei Yamamoto, the Thunderer…”

“The one and only,” our boss chuckled. “Pleasure to meet you, Ilya Reutermann. Ah, these are Katy Shimizu and Isayama Tore, our newest recruits.”

“A pleasure.”

“Nice to meet you.”

Ilya was a tall man with reddish-brown hair that matched his thick mustache. His ruby-red eyes were hidden behind large, round glasses, which he put into his shirt pocket as he greeted us.

“Likewise, kids. I hope we all get along well.”

“Kids?” Repeated Katy.

After the introductions, Shinpei took Ilya to meet the rest of the team. Many already seemed aware of his arrival.

“As I’ve mentioned to some of you, Ilya is a contagion researcher from Division 1, one of the best in our company,” Shinpei explained.

Wow, it’s my first time meeting someone from Division 1…

“He’s here to collaborate on some high-priority cases. Many of you will work with him, so I hope you get along.”

“It’s a pleasure, Division 3 friends! Let’s work together to save lives!”

Hours later, lunchtime arrived.

After introducing us to Ilya, Shinpei began explaining him our processes, which differed slightly from those of other divisions.

“Shall we eat with Hiro and Felix?” Katy asked, bento box in hand, as she approached my desk.

“Sorry, I’m meeting a relative today. I’ll be out for a couple of hours, but I’ll work double when I get back so we can leave early.” I smiled.

“Oh… okay.”

Over the past few weeks, I’d had the good fortune to grow much closer to Katy. We even ate lunch together regularly now! It was a relief to finally call her a friend.

“I’ll try to get ahead while you’re gone. Don’t stress—enjoy yourself.”

“I will.”

…

Unfortunately, the meeting awaiting me was far from pleasant.

I won’t let your death be in vain…

I told myself, staring at my reflection in the elevator’s mirror. Upon reaching the lobby of Cellos Robotics, I ran into Shinpei.

“Heading out?”

“Yes, I’m meeting a relative.”

“Ah, that’s good. Isayama…” Carrying a bag of his favorite Chinese takeout, Shinpei stopped me.

“Yes?”

“I’m not judging you, but why haven’t you told Katy about your father? Your partner’s supposed to be like your best friend. Keeping something this important from her could backfire in the long run...”

I hesitated, clenching my fist against the weight of that awful memory. Then I recalled my dad’s final words…

“You’re right, Shinpei.” I forced a smile.

“Isayama…”

“I’m really happy with how much closer Katy and I have become this month. That’s why I don’t want to ruin it with unnecessary sadness. Just this once—I promise.”

I pretended to leave.

“You’ve really grown, little pup,” Shinpei muttered. “All right, just wanted to give you a heads-up. If it’s just this once, nothing bad should happen.”

“Great. See you in a couple of hours, boss.”

“Take care.”

Without further delay, I returned to the pristine streets of the central districts.

I soon found myself walking through the clean streets lined with blooming trees in District 1. Unexpectedly, I stopped in front of a small manor, a familiar house in this district.

The gate was sealed with the quarantine team’s tape, and the garden was littered with trash and broken furniture. The state of the windows and the door left no doubt—that house had been abandoned.

What could have happened to them…?

After a moment’s hesitation, I continued walking. A subtle bitterness settled in my chest as I left, pondering what had become of Aiko and Shizuka. What could have driven them to abandon their home after Joshua Cam’s death?

A kilometer later, I found myself on a bustling street filled with screens and LED displays.

I stepped into a modest café.

Decorated with wood and bathed in light from its large windows, the café had a warm and inviting atmosphere. I weaved through the tables until I reached the man I was looking for.

The old man sipped a cup of coffee with milk, his ever-present red notebook resting under his watchful gaze. He was none other than my former hospital mentor and one of the city’s most renowned doctors.

“Yamaguchi-sensei, it’s good to see you.”

“Tore, sit down,” he said, his eyes lighting up upon seeing me.

He hadn’t shaved in days, giving him an unkempt appearance that didn’t match the image of the respectable man I once worked with.

We hadn’t seen each other since that day…

“How have you been, sensei?”

“Please, don’t call me that anymore…”

“Huh? Why not?” I sat across from him.

“My days as a doctor are over…” His face looked even more worn than it had the day I left the hospital.

“If this is about my father, I’ll tell you right now—I won’t accept it.”

“Tore, are you eating well?”

“Did you hear me, sensei? If you leave, what will happen to Tatsumi?”

“Kageyama will soon follow in my footsteps…” He tried to sip his coffee again, but his hands trembled visibly.

He barely managed to set the cup down without spilling it.

“Yamaguchi-sensei…”

“Before we get into anything else, tell me—can I help you with something?”

“I’m sorry, sensei, but I won’t let you feel guilty about my father’s death. Look at me—I’m doing just fine.”

Defeat was written all over his face.

“You know, I miss him a lot. But he wouldn’t want you mourning his death—he wouldn’t even allow it to his son. So tell me, why did you want to see me?”

“You’re right.” He opened his notebook. “Forgive me—it’s the first time I’ve ever felt fear after a loss.”

“Fear?”

The red notebook was filled with notes and scribbles, much of it unintelligible to anyone but its author.

“That’s right… After Hikaru Tore’s death, I felt fear…”

“Is this about the fifth evolution?”

“Yes. As medicine stands now, a new evolution of the S-Flu could deal a devastating blow to civilization. Your father experienced symptoms that align with what I’m currently investigating…”

I didn’t know what to say. The weary man was undoubtedly correct.

“That’s why I have to leave medicine behind… I need to dedicate myself entirely to this research. The risk is just too great.”

“What if it’s not an evolution?”

“I’d rather waste the rest of my days investigating isolated cases than risking being unprepared. My vocation hasn’t changed—the magnitude is clear.”

Those were the words of a man tired of losing, a man who, despite his age and the weight of time, was determined to try one last time to save lives.

“I can’t allow more people to suffer the same fate as my student’s father,” he said quietly, watching his hands tremble.

“And me? Why did you want to talk to me?” I asked, still confused.

“I just wanted to ask you to be careful out there. We don’t know what’s coming next…”

The old man stroked the pages of his notebook, resolute in his decision to devote himself wholly to this cause, even if it meant chasing shadows until his final breath.

What if those cases were mere coincidences?

What if it was already too late to stop the devastation of the fifth evolution?

What was I supposed to do with this information?

As if dealing with the rot of S-Flu wasn’t already enough of a challenge for me…