Tooru Sasayama

A good-hearted but relatively inept police detective who assists Kazuhiko and Machi. He often uses their criminal profiles to appear more skilled than he actually is (as he feels he lacks the "life experience" to comment on others). In truth however, he cares a great deal about his troubled colleagues and works to assist them in any way he can.

The character also appears in the Kurosagi series as an older man who is bald, scarred and missing a leg. The older Sasayama no longer works as a detective (due to his injuries) and instead directs Shinjuku's Social Welfare Office.