The story of a boy and a monster. The action takes place in two worlds: the world of men (Shibuya in Tokyo) and the world of monsters (Sibutenmati). In these two worlds that should never be crossed,live a lonely boy and a lonely monster. But one day a boy lost in the world of monsters and became a disciple of Kumatetsu monster. Since that time, when everything changed, the boy took a new name - Kuhtai.