Tsugunai is a hentai novelty from Studio Pro released in June 2022 based on the visual novel of the same name by the private circle "Blue Gale".

The main character of hentai lives with his sister Nana. They were left all alone after an accident that happened to their parents. One day, by a terrible coincidence, Nana fell into the dirty clutches of a group of concerned influential old men and was deprived of her innocence and raped in a circle... The main character could not accept the injustice of the world and decided to take revenge. He got a job as a teacher at a private women's academy, where the daughters of lustful old men study, and soon created ideal conditions for revenge...