In a world where dreams hold mystical significance, Souya Kuroi awakens from a haunting dream featuring a destructive dragon bathed in rainbow hues—a symbolic battle against inner rage. Plunged into a harsh reality where he has lost his parents and memories to a mysterious incident, his existence transforms into a living nightmare. Cared for by the enigmatic duo of the lively maid Ginko and the enigmatic feline named 'Sensei,' Souya's sole recollection remains the dragon's fiery chaos. However, his fate takes a sharp turn as Saromisaka City faces a peculiar threat in the form of a UFO resembling a teddy bear. When conventional defenses falter, seven enigmatic figures emerge to combat the alien intruder with dazzling rainbow lights mirroring Souya's dream. Yet, as the extraterrestrial menace is vanquished, these seven saviors find themselves challenged by a new foe: Souya himself. Driven by a thirst for retribution against those who shattered his former life, he embarks on a vendetta against these self-proclaimed 'heroes,' thrusting himself into a cosmic conflict of epic proportions.