Yami-Hara (Hardcover) (novel)

"When they come, someone dies..." After a quiet boy named Kaname joins the class, Mio reaches out to him, hoping to help the odd boy settle into his new environment. Kaname takes to her a little too well, however, asking to come to her house and then showing up all the time. Frightened, Mio seeks help from an upperclassman she admires...but the nameless wickedness is already coming.

It's close. It's growing. A horror-mystery novel by famed author Mizuki Tsujimura.