Fukai ni Nemuru Oujo no Abaddon

Based on the erotic doujin game by SAKURAPRIN (さくらぷりん). No one dares to live in the dark forest... Yamanobe, a friend and university professor of Aya Koji, the owner of the Aya Koji House, is interested in this ancient mansion and, with the permission of Aya Koji, comes with his assistant to search for the various phenomena that occur there… (Source: AniList)