Bela: Humanoid Monster(2020)

Overview:

Kosuke Nitta has been toiling away on a 50th anniversary DVD box set of the classic anime TV series Humanoid Monster BEM. While hunting for a new special feature to attract more buyers, the timid advertising employee finds himself falling into the maw of madness after he discovers the original cut of Bem's final episode. At the same time, a tragedy has left a local high school reeling in the aftermath. What's the connection between these harrowing events? A mysterious girl by the name of Bela.