Once every 3,000 s a monstrous being known as the Overfiend enters the human dimension in order to destroy it. According to legend, our world must be overturned to pave the way for a future in which humans peacefully co-exist with a world of Man-Beasts and a world of Monster s. People scramble amid the rubble of a dying universe in this film that single-handedly created the "erotic grotesque" genre of Japanimation.