Momiji tells the story of Masaki, a seemingly normal high-schooler in every way. Spending his time with his 2 friends Hiroaki and Shuuya and the girl he is interested in Yuri.
But he also has a terrible secret, 5 years before he caused by accident the death of his childhood friend and crush, Kaede. In pure shock in front of the dead body he could do nothing but recite an incantation written in a strange book he found by chance, a spell that could seemingly resuscitate the death.
Waking up from passing out the body of Kaede disappeared without a trace, the next day her family too vanished. With only the vivid memory of her death in mind, Masaki didn’t felt sadness or guilt over losing his friend but rather fear at being caught as a murderer.

And 5 years later while people start to disappear again, Kaede reappears in front of Masaki looking exactly the same as 5 years ago, is she the illusion of his deranged mind, or…

[From hadlerblog]