Yuurei ga! Yoru no Kyoushitsu ni

Rei Mikogami has been transferred to Inugami Municipal Junior High School. When he went to check out the school, he saw a hallucination of blood in the shape of a human figure in front of the school building.
On that very day, a murder occurred at the junior high school. The victim was a male student named Yui Yamazaki, who—just as Rei had seen in his hallucination—had been thrown against the blackboard by an unknown assailant and died from multiple contusions. Who on earth is the murderer...?

(Source: Kaiki Manga no Anagura, translated)