Kara no Kioku

Synopsis:

Rei begins his day feeling nervous and uneasy because he recently moved to Tokyo and it is his first day of high school. Along with his anxiousness, Rei enters the classroom, where he is abruptly overcome with a bizarre dream and a chest discomfort amid the commotion. A tiny creature is waiting for Rei on his desk when he awakens. Rei goes home, dismissing it as a part of his dream. To his astonishment, though, there are a lot of other odd animals of all sizes and shapes who wander the streets and appear to be invisible to other people. Rei's life is permanently altered when he sees a tall, one-eyed figure wearing all black and grinning at him. He has a lot of questions and the little thing from before is following him.