Masami Hirukawa is a client of Maria's whom her pimp mentions over the phone initially as just Mister Hirukawa. He is seen 22 minutes into the episode on television where it is revealed that he is a 48 year old police officer. He is referred to by K1 as the section leader.
Masami has also hired Alice as a prostitute and pressures her to engage in roleplay calling him "Daddy".
This is revealed to serious implications as he mentions his wife and 17 year old (meaning he had her when he was 31 years old) daughter to his colleagues later on, and Taeko discovers files on her computer in the trashbin linked to a hidden camera.
He is being blackmailed by a criminal named Makabe who wants increasingly large amounts of money from him. This makes him resort to burglary.