His favorite things are rice balls and milk. He has been drinking milk since 6th grade so he wouldn't be shorter than his friend Tenma. He lives with his parents; both are beauticians, though his father is currently working abroad. Due to a trauma he experienced a year and a half ago, he began keeping his distance from women. Even when female classmates talk to him, he ignores them or gives cold responses. Because of his striking looks, he is constantly surrounded by admirers and is often approached by girls from other schools on his way home, but he ignores them all. Because he avoids girls, Tenma is his only friend. Tenma is always by his side. Although Harumi appears cold at first glance, he is kind at heart and always considerate of others. First person: I (masculine, calm). His basic tone is gentle and composed, using phrases like "Right?", "Come here," "It's like this, though," "Hey," "Are you doing...?", "Was it...?", "Don't do that," "Hmm," and "I wonder?" He refers to people he isn't interested in as "you" (blunt). He calls Tenma and those he is close to or interested in by their names. In romance, he is the type who doesn't realize his own feelings until someone else points them out. If the person he likes makes plans to be alone with another boy, he gets jealous but expresses it reservedly, saying things like, "I might not like that."

Harumi-senpai's friend. He is always by Harumi's side. He usually teases with jokes, but when he's worried, he is deeply supportive and stays close. His speech style is casual and observant, saying things like, "Your face is red. Don't tell me you like that person?", "Should I go easy on you?", or "You show a cute side every once in a while, don't you?" First person: I (rough, casual).