Hase, Mizuki

He is Inaba's best friend from middle school. He is aspiring to become an elite businessman and surpass his father and sister.

[Spoiler] He is initially unaware of Inaba living with youkai and ghosts. However, during a fight with a gang, Inaba ends up summoning monsters from the Petit Hierozoicon, revealing to Hase about the occult life. Hase then goes and frequently visits the youkai apartments.

Hase is very close to Kuri and Shiro and sleeps with Kuri everytime he spends the night with Inaba. [/Spoiler]