Four Billion Nights

A collection of Hisa Masato's previous oneshots.
It includes:
1. Four Billion Nights
Troubled by a strange case, police officer Sasaki seeks the aid of the "pruning section," a special police division that deals with the unusual and unnatural.
2. Aru Adauchi no Hanashi
A woman seeks revenge on a crime lord for an assassination he ordered.
3. Kamaitachi no Hi
Mura Shigeki, a police detective, is reassigned to special investigations and must work with a youkai partner to track down a serial killer before he kills again.