When a normal high school student named Kairo is replaced by someone from another universe, he finds himself aboard a massive prison ship drifting through space, far from Earth.
Rescued by a girl in a modified astronaut suit, Kairo is thrust into a world where the lines between technology and power blur.
As he struggles to understand his new reality, Kairo discovers that a strange, illuminated creature has fused with him, granting him unexpected abilities—but at a cost. With his body now part of a cosmic ranking system tied to his strength, his only hope is to find a way back home.
However, his plans are complicated when the girl reveals her own mission: revenge against a powerful villainous group that controls the galaxy.
As they rise through the ranks, Kairo must confront his growing powers, his fractured identity, and the dark forces pulling at the edges of their world. Will he ever return to Earth, or is his fate forever intertwined with the stars?