In Peach Boy Riverside, a magical world is divided by deep hostility among humans, demihumans, and oni. Princess Saltorine “Sally” Aldike leaves the safety of her kingdom in search of a man named Mikoto Kibitsu, and her travels steadily expose how little she understood about the world she was born into. As Sally crosses each frontier, she learns the brutal truth hidden by her lineage: the oni possess enough power to erase humanity, and the conflict between the three races is far more dangerous than royal stories suggested.
Marked by a peach-shaped sigil that grants her superhuman strength, Sally can face powerful oni head-on, yet she refuses to judge humans, demihumans, and oni by race alone. Rather than accept the cycle of hatred around her, she keeps hoping that coexistence is still possible.
Mikoto, who shares the same power but wields it with far greater mastery, takes the opposite path. Driven by a relentless desire to kill and torment every oni in existence, he is a terrifying counterweight to Sally’s idealism. As their journeys repeatedly intersect, Peach Boy Riverside turns their opposing convictions into a struggle that may decide whether the three factions can ever live together—or whether the world will collapse into annihilation.