Chapter 20: Absolute Dungeon Conquest Note

School was canceled today, a side effect of yesterday’s incident. It was a short-lived start to my academic career, but it gave me time.

I sat in my room, reopening the diary I’d first discovered the day I woke up in this world. The cover was worn, the pages holding the weight of three years of someone else’s life.

"Let’s see... I only skimmed it before, but looking at it like this, it’s actually impressive."

The entries were mostly about his childhood friend and his best friend. They were filled with memories of diving into Dungeons together. Toward the end, the ink seemed to dance with the joy he felt when Ayane finally reached S-Rank.

The writing was meticulous, summarizing every event with painstaking detail. I could understand the logic behind his actions—after all, he was "me," even if we were from different worlds. If I studied his behavior in these pages, I could probably mimic him well enough to avoid slipping up around people who didn't know about my "memory loss" cover story.

I needed to stay at Meikutsu Academy. To do that, I had to avoid drawing unnecessary suspicion. That school was the front line for high schoolers conquering Dungeons. It was bound to have archives and data I’d never seen before. It only made sense to utilize every scrap of knowledge available.

"So... according to this, I really was just a Supporter."

The principal had said as much, but seeing it in writing was different. The diary didn't explain how I—a person with zero magical power—managed to function as a Supporter in a lethal Dungeon environment. But one thing was clear: the original Reima had been capable.

I still didn't fully grasp the sheer scale of an S-Rank Adventurer’s power, but if I translated it into the power scales of my old world, the absurdity became clear. Pushing someone like Ayane to that height wasn't something a mediocre person could achieve.

"Is there anything else?"

Information was the only currency that mattered right now. I stood up and began scouring the room. If my parents were home, I could have just asked them, but they were both at work. I was on my own.

"I was hoping for a weapon, at least. Oh, right. [Summon]."

When it came to detecting mana, my companion Lycoris was far more efficient than I was. Given the popularity of Dungeons and the state of this world, the "me" of this reality should have been making a decent living. I was betting on him having a hidden stash.

"Reima. I found something."

Lycoris appeared, handing me a small, empty tin case.

"That was fast... Wait, is this an invisibility ward?"

I opened the tin. To the naked eye, it looked empty, but my fingers brushed against something solid. Based on the texture and shape, it felt like a notebook. It was smooth, almost silky to the touch.

Usually, these things came in pairs. If it was a notebook, there had to be a specific tool to read it. I searched the desk and found a pen sitting in a case, humming with a faint magical resonance.

The moment I gripped the pen, the object Lycoris was holding flickered into view.

It was a cheap notebook, the kind a middle schooler might buy at a convenience store. On the cover, written in clumsy, unrefined script, were the words: Absolute Dungeon Conquest Note.

He had even been diligent enough to date it.

The first page was dated 2015. He’d started this in the sixth grade. The first entry was blunt: No magic! Studying is hell, I’m so tired! I let out a short, dry laugh, but the next line caught me off guard: But it’s my dream. It was almost painfully wholesome.

As I flipped through the pages, the tone shifted. The entries became detailed logs of Dungeon conditions. It was a record of blood, sweat, and tears shed so that he, Ayane, and Shiki could become Adventurers together.

To be the best Supporter, I need knowledge first! And stamina! one entry read. Another followed: I lied and said I could handle it. I really regret that. I have to work twice as hard for the next two days to catch up. Lying is bad...

The habit of bluffing to save face is the same, I see.

But as I kept reading, the evidence of his effort became overwhelming. The "me" of this world had pushed himself to the breaking point, over and over again.

"This is the fourth one already? I wrote way too much."

Studying, interviewing experts, physical conditioning, endless practice... he did it all for those two. Reima’s emotions bled through the paper. He wanted to be able to look his childhood friends in the eye and tell them everything would be okay. He wanted to be the one to pave the way for them. He knew he lacked the mana to stand beside them as an equal, so he dedicated himself to ensuring their overwhelming talent reached the future it deserved.

A dark, bitter feeling began to pool in my chest. It felt like I had reached into this boy’s life and stolen the fruits of his labor. The guilt gnawed at me, but I couldn't stop reading. I had to know where his path led.

The fifth notebook: Dungeon Characteristics. The sixth: Monster Encyclopedia. The seventh: Efficient Support Methodology.

Finally, I reached the eighth notebook, written around his second year of middle school.

It hurts. It’s not enough. To get Ayane to S-Rank, I’m not enough as I am now. I’m dragging them down... What do I do? It’s simple. I just have to work harder. I’ll do it until I can stand tall and say "I’ve got this."

The page was warped, stained by dried tears.

Because it had been written with a mana-imbued pen, Reima’s lingering will resonated through the paper. This kid had spent his whole life fighting off the urge to say "it can't be helped."

I’m not trying hard enough. I wonder if I can be a hero like them... But the only thing I’m missing is effort. The heroes of the old stories didn't have magic either. That means I can be one, too. I can be a hero.

"...This is the last page."

Finally. We’re taking the S-Rank trial. We’re the youngest ever to try. Our party—me, Shiki, and Ayane—is finally being recognized. It’s all paying off. After this, I’ll finally...

The notebook ended there.

Lycoris was peering over my shoulder, silent. The air in the room felt heavy, suffocating. I didn't know exactly what happened during that trial, but since Ayane was currently an S-Rank, the mission must have been a success.

"Hey, Lycoris. I’m going back to my original world. No matter what it takes."

"...Reima?"

"I’m going to dive into the Dungeons. I have to find a way to give this body back to him. To the real Reima."

Dungeons were repositories of the unknown. There had to be a way to reverse this. But until then, I had to keep my identity a secret. If the truth came out, it would trample all over that kid’s hard work.

He was me. But he was a hero—someone who lived and breathed for the sake of others. He wasn't like me. In the other world, I was a man who only knew how to take and how to kill. He was a hero who moved for the sake of everyone else.

"I’m giving it back. I swear it."

The words slipped out before I could stop them. Lycoris looked at me, her expression strangely lonely, but she didn't say a word.

"Alright. We still have time. Let’s head to a Dungeon. I need to start putting in the work."

My mind was made up. There was only one way forward.