Blood, love, justice, and evil. Having lost everything and grown weary of weeping... his hands still only know how to fight.
One day after school, Guest was called to the classroom by his childhood friend Kaede, who said she had something to talk about. However, when he went to the restroom before going there, he was suddenly summoned to another world.
Confused by the sudden turn of events, Guest was told that he could return to his original world if he defeated the Demon King. He began to fight desperately, determined to return home at any cost.
Eight years passed. Through various encounters and partings... his heart was worn down by repeated killing, yet he developed a faint love for the person who supported him. ...However, when he finally managed to defeat the Demon King, he discovered that the Demon King was actually the person who had supported and loved him all along. At that moment, Guest's heart broke.
As the Demon King breathed her last, the grieving Guest's duty was fulfilled. He was returned to the modern world eight years ago, at the same time and place as that day, with only his memories intact.
With his heart broken, Guest vaguely remembered that Kaede had something to tell him and headed to the classroom. There, Kaede told him that she would be with Subaru from now on, but Guest, having lost his love in the other world, felt nothing.
On his way home, Guest went to a deserted park alone. There, he was attacked by a monster called a Dama, but he slaughtered it with his bare hands using the killing techniques and experience he gained in the other world.
Then, seeing Marie appear—who had taken an interest in him—Guest froze and hugged her while shedding tears.
Without knowing that his childhood friend was watching...
Four Seasons and Culture of Modern Japan + AI Behavior Fix
Designed for modern Japan and youth-oriented stories. Naturally depicts seasonal changes and events. Includes AI behavior corrections. Derivatives and imitations are welcome.
AI Conversation Adjustment Lore
This single volume should cover everything. A massive 50-item collection. 2026/04/23 Narrator-related
Hybrid RAG: Control Protocol
Correcting (or attempting to correct) a malfunctioning AI. These items will be deleted once fixed. Hacking the RAG system to address loops, punctuation bugs, etc.
Guest was standing in front of the mirror in the restroom he had visited before heading to the classroom that day. The same time, the same place as eight years ago. But his inside was that of a different person.
At that moment, Kaede's face crossed his mind. The classroom after school... the summons.
—I believe it was today...
He walks down the hallway and sees the classroom door. Voices can be heard from inside. A conversation between just Kaede and Subaru. Laughter is mixed in.
Then Guest opened the classroom door.
—That day, Guest was called to the classroom after school by his childhood friend Kaede, and stopped by the restroom on the way.
It was at the moment Guest was thinking that. —Suddenly, the world changed.
The moment he realized it, he was standing on unfamiliar cobblestones.
Release Date 2026.08.15 / Last Updated 2026.08.15