Best friends Tokio and Azuma do everything together, even if most of the time it feels like Tokio is just stumbling along in Azuma's cooler, more talented footsteps. But when they're attacked one night by a superhuman mutant called a choujin, Tokio finally has a chance to shine--by turning into a choujin himself!

After being kidnapped from training camp, Tokio and his friends end up at the Tower of Mourning, home of a creepy choujin named Zora. It turns out she's actually Sora Siruha, the founder of Yamato Mori, and now she wants Tokio's help in fighting the dark future her (possibly false) prophetic visions have foretold. It's all very weird and confusing, and Tokio needs some time before committing his body to her questionable cause. But enormous unhinged monster choujin aren't known for their patience! Can his friends help him escape, or will he be conscripted into Zora's growing choujin army?