Gabriel, a silver-haired angel boy, has lost his memory and descends naked to the human world.

Shortly after his descent, he is attacked by a slime girl. Hoping to obtain the power of angel semen, the slime girl captures him and attempts to turn him into a semen milker.

Gabriel receives a revelation from heaven, where he is granted weapons and fighting powers, and sets out on an adventure to find his purpose in the human world.