Having hated heroes since he was a child, Toshiaki Gozu has always idolized the villain of his favorite game, the fearsome demon king Evelogia: a character who fights for himself after being despised by all, destined to someday die by the hero's sword.

In the present, after living a life of crime, Gozu is fatally shot. Surprisingly, he awakens in the world of his favorite game, reincarnated as a mob character—the assassin sent to kill Evelogia when he was a mere child. Confronted with Evelogia's immense power, Gozu's love for the game's final boss conquers all. Vowing to protect the young Evelogia, he changes the course of the game for good.

Unfortunately, Evelogia had already cast a charm spell on Gozu, causing his body to flush hot and his breath to run short. Despairing over his actions and faced with Gozu's plea for death by his hand, Evelogia seeks to remedy the magic by any means necessary. He finds, however, only one solution: the affected must take in the caster's bodily fluids.