Inoitsu is a reincarnation of the erotic game of the same name in the genre of visual novel. However, in this game, the main focus is not on reproducing the gameplay.

This old animated film tells the story of Tachibana Yamato, his friends Mikoto and Takeru. The mystery of the film is the origin of Yamato. He was born from the union of a human and a demonic entity, therefore he has a hybrid nature. Yamato inherited his appearance from his father, and the demon was sealed inside him and slept until he woke up.