Chapter 0:

Interrupted

Nido Isekai Tensei Shitta: Isekaid Twice


I was fifteen years old, disgustingly rich, and wildly unqualified to exist.

Seriously. I had staff who did everything, woke me up, brushed my hair, cooked me gourmet meals I didn’t deserve and still had the nerve to call me Kaito-sama, like I’d earned it.

I hadn’t.

Academically, I was bottom of the barrel. I skipped school more than I showed up, and when I did show up, it was either to sleep or mentally clock out mid-class. I’d long since accepted my place in the ecosystem: apex freeloader.

Why?

Simple. My mom died and left behind a ridiculous inheritance.

We’re talking mansions, cars, private dojo, and servants who wear suits indoors kind of inheritance. And apparently, when your mom is some big-shot warrior with a mysterious past and a scary amount of gold bullion, you get to retire before you hit puberty.

So yeah, I coasted.

I spent most of my days glued to anime, games, and other… niche internet hobbies. Not proud, but not apologizing either. I knew how to live. And by “live,” I mean rot in a gaming chair, blast questionable content at max volume with noise-canceling headphones, and feel zero shame.

Of course, I was trained in swordsmanship and martial arts from the time I could walk. Mother’s orders.

She was all about discipline, spirit, honing the body, all that traditional warrior stuff that didn’t vibe with my natural NEET energy. I’d protest, she’d glare, and then I’d find myself dodging a shinai like it was a guided missile.

Even after she passed, I kept training. Not because I liked it. Not out of respect. It was just… built into me. Something about drawing a blade made the world go quiet.

Anyway, fast forward to now.

It was a Thursday. Or maybe Friday. Didn’t really matter. The day started like any other: wake up at 2 PM, ignore the tutor knocking, slide back into my blanket nest, and open tabs I’d be ashamed to explain in public.

That was the plan.

What actually happened? Far worse.

I had just booted up a certain anime involving magical girls, potions, and clearly non-PG plotlines when I heard footsteps.

Minako-san. My personal attendant. Mid-30s, looks like she walked out of a romance manga, but acts like a disappointed older sister from a soap opera. She’d been with us since I was born, and at this point, I was 85% sure she was the only reason I was still alive.

“Kaito-sama,” came her voice through the door. “Your math instructor is here.”

I lowered the volume, slightly panicked. “I’m busy!”

“Busy doing what?”

“Training my… right brain!”

There was a pause.

“Open this door.”

And that’s when my life derailed.

Right as she turned the knob, a blinding blue circle lit up under my chair.

“What the?!”

I barely had time to flinch. The next moment, gravity disappeared. My chair disintegrated into glowing dust. The world folded like paper. My heart tried to eject itself from my chest. Then everything turned blue. Completely blue.

I opened my eyes. I was floating in a massive translucent orb. No floor. No sky. Just glowing blue, like a magical screensaver gone rogue.

I panicked.

Not because I was in an interdimensional void. Not because I had no clue what was happening.

No.

Because my screen was still open.

The exact anime. On full blast. Loud enough to be heard in three prefectures. And Minako-san had walked in just as I vanished.

“She saw it…” I muttered in horror. “She SAW IT. I’m going to die again just from the shame.”

[System Notice]
Welcome, Kaito Amakusa.

I jumped.

The voice was huge. Not loud, just… there. Like it echoed straight into my bones.

You have been summoned across space.

“Okay, wait. First of all who are you? Second, I didn’t agree to any of this, and I was in the middle of something extremely private. Can I go back for like, two minutes? Just to shut the tab?”

Denied.

“What do you mean denied? This is a matter of a man’s dignity! Can’t you overlook it just this once?”

You have arrived in this realm with your original body intact.

“Are you even listening! Oi!”

You have been granted two Unique Skills.

I blinked. That actually sounded useful.

“Go on.”

First: Yin and Yang.
This skill creates a dual-mind structure. One reflects your current state. The other, your opposite. Intelligent. Strategic. Morally sound.

“Mhh… So, an actual functioning version of myself.”

Correct. Yin: You. Yang: The version of you that makes good decisions.

“My decisions aren’t all bad, you know.”

Subskills include: Thought Acceleration, Parallel Processing, Chant Cancel, and All of Creation.

“Those sound super useful, but I’ve got a bad feeling about this.”

Second: Plunder.
You may steal abilities from enemies you defeat, or significantly weaken them.

“…I swear to God, if I get summoned to some fat, obviously suspicious King and Princess and get told to defeat the Demon Lord, I’m going to lose it.”

Additional traits:

Race: Demon Noble – Human Hybrid
Resistances: Fire (Medium), Lightning (Low), Wind (Low), Physical (Mid), Bleed (Low), Holy (Low)
Immunities: Poison, Charm, Dark Attribute

“Wait. Demon Noble? I thought I didn’t reincarnate. I’m human, you know. Oi, answer me!”

Preparing transfer to designated location.

“Already?! Can I get a sword or at least a starter pack?!”

No answer.

The space bent again, like ripples through glass. I barely managed to yell, “I SWEAR I WASN’T WATCHING THAT FOR THE PLOT!” before the world dropped me straight into darkness.

When I woke up, my face was pressed against something cold, wet, and slimy.

A cave. Real this time. Dark, rocky, some glowing moss on the walls. And the faint sound of… something breathing deeper inside.

“Oh fantastic,” I muttered, pushing myself up. “The starter dungeon. Because of course.”

I checked my hands. Still human. No claws, no horns. My clothes would definitely make me stick out.

My body felt… different. Like someone had turned off gravity’s rudeness. Every movement sharp and fluid, like a sword still humming from being forged.

I took a deep breath.

“Alright. New world. New life. New chance to prove I’m not completely useless.”

Observation activated. Scanning surroundings.

“Ah, there you are, Yang. Was wondering when you’d chime in.”

You’re currently in the deepest level of this cave. Hostiles include serpents, boss slimes, drakes, centipedes, and more.

“Eh, what do you mean the lowest level? This is a joke, right? Was I summoned just to die?”