Idaten, a pure-hearted makemono youth, surfaces in the post-apocalyptic aftermath of the Overfiend's catastrophic rise. As part of a new hybrid race—half-beast, half-demon—he bands together with fellow makemono survivors Buju, Gashim, and Ruddle. They embark on a pilgrimage to Osaka, fleeing the tyranny of Caesar in Tokyo to challenge the Chōjin. Amidst the arduous trek, Idaten nurtures an unrequited affection for Himi, another companion. Yet, amidst surrounding chaos, his feelings remain one-sided and unresolved.