Ao Oni the Animation  

Aooni The Blue Monster, あおおに ～じ・あにめぇしょん～

In typical high schools, numerous stories and rumors circulate-some scandalous, others joyful, and a few unsettling. One such tale is about monsters residing in an abandoned mansion beyond the town limits. Despite the warnings, Hiroshi and his friends Mika, Takeshi, and Takurou are unable to resist the allure of these rumors. Driven by curiosity and the desire for a challenge, they venture into the manor to investigate and prove their courage. Each member of the group feels an overwhelming sense of fear as they approach the mansion. Upon entering, they encounter Ao Oni, a blue monster who attacks them mercilessly. As Hiroshi and his companions attempt to solve the intricate puzzles within the manor and evade their new foe, they discover that their actions lead to disastrous consequences.