The Gate of Sorrows — Miyuki Miyabe

A series of murders shocks Tokyo's Shinjuku ward, but Shigenori, a retired police detective, is instead obsessed with a gargoyle that seems to move. College freshman Kotaro launches a web-based investigation of the killer, and comes to find that answers may lie within an abandoned building in the center of Japan's busiest neighborhood, and beyond the Gate of Sorrows. In this adult sequel to Miyabe's The Book of Heroes, you will meet monsters from other worlds and ordinary horrors that surpass even supernatural threats.