Ohno Shiori is just an ordinary high school girl. One day, Umenokisaka Bella comes to her class as a transfer student. Bella is given the seat of the recently deceased Sasaki Kozue, a close friend of Shiori's that died in a tragic accident. Shiori notices that Bella has the same kaleidoscope key chain that her and Kozue also owned. Due to her personality, Bella soons becomes a victim of bullying in the classroom but there is something strange about her. What is the truth behind the relationship between Kozue and Bella? What is the truth behind Kozue's accidental death?

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.