Debochi Amon, a fervent 14-year-old, had a peculiar habit of literally steaming up. Amid his ordinary life of school routines, friendship circles, and harboring feelings for his classmate, Shinomoto Sako, a startling event unfolds. Following a steaming episode, a mysterious third eye materializes on Amon's forehead, ushering in the arrival of a chatty owl entity named Goomin. Both bewildered by the newfound situation, Goomin enlightens Amon about his latent ability in Pyrokinesis. Amon's fiery prowess amplifies with his surging passions, especially his ardor to safeguard his crush, triggering a metamorphosis into a formidable demonic entity fueled by unchecked desires. Tasked with defending the human realm from celestial threats, Amon grapples with mastering and harnessing his incendiary gifts amidst the looming shadow of Angels.