Mushoku No Sonzai 無色の存在 (Colorless Existence)

We enter the school doors. The lockers and halls empty. This was normal. Class was in session.

"Susumu. You should try finding yourself first."

"Finding myself?"

Ren stares out of a window in the hallway.

"Yeah. My time travel isn't perfect. So you should hurry."

"What do you mean?"

Ren continues to stare at the baseball field outside. He looked somewhat sad...
I walk to the window, and gaze at the field.

"Um...Do you like baseball?"

He doesn't look at me, but instead continues staring endlessly at the field.

"Yeah."

His eyes close.

"We angels, were once human too..."

Ren steps away from the window, and leans against a wall near a classroom.

"Well, it doesn't matter right now. It was long ago, after all."

"I see."

His sad face suddenly changes to a smile, as he glares at me.

"Anyway, I should explain what you need to do. Summon your Stilus"

"Stilus?"

"Your pen. But, it's actually called a Stilus. If you call its actual name, you can summon it instantly, no matter where you are."

"Ah. That's right. It suddenly disappeared after I first summoned it..."

I suddenly remember the feeling. The feeling of wanting to escape that dreaded prison. That mental hospital.

"Even at the mental ward?"

"Mental Ward?"

His eyes give a confused glance.

"Well, as I said, Anywhere."

I extend my hand, and feel the warm sensation again...

"Stilus."

The Stilus manifests in my hand, the flames suddenly turning white. A strange flame. The flames glow faintly at the end of the Stilus.

"Heh? So you could summon it that fast after all."

Ren opens the door to a random classroom.

"Now, let's go in here. I'll teach you."

"Eh? Why in here?"

"It'll be fine. Just trust me."

Sighing, I enter the class. The students sitting quietly at their desks as the teacher explains Mathematical equations. I actually did like math, though not for its homework...

"Okay. Do you see anyone you know?"

I search the room. Unsurprisingly, I don't see anyone I seemed to know.

"No."

"Well, that's okay. Let's walk to that guy over there~"

Ren points at a boy with broad shoulders and short cut blue hair.

"H-Hey...I don't know this guy."

We approach him, and I wait anxiously for Ren.

"What are we going to do?"

"Hm? We're going to learn the basics."

"Basics?"

"Right! Make yourself visible to this person!"