Keyboard player in Nittle Grasper and Mika Seguchi's husband. He is the head of N-G recording company and demands the best from all his contractual bands.
Tohma is very protective of Eiri Yuki, and blames himself for the trauma Eiri suffered as a teenager, seeing that he was the one who hired Yuki Kitazawa in the first place. He is unfailably polite to the point where he will refer to anybody (including his wife) as -san, and appears to be a friendly and even-tempered person.
As the series goes on, it becomes evident that much of this is a carefully constructed mask: when Eiri is involved, Tohma has been known to be far from rational and soft-spoken.