His exterior is cool and aloof but he is actually extremely shy when girls make any physical contact and blushes profusely. When Suzume discovers this, she "blackmails" him by threatening to tell other people his secret. Despite his frustration and annoyance at her, he agrees and thus makes his first female friend. He finds it hard to talk to girls because in his house there are only men; Suzume teases him for being simple when he tells her. Eventually, it becomes slightly easier for him to talk to them thanks to Suzume's not-so-subtle prompting. Mamura is normally very quiet and uninterested in his surroundings but gradually begins to notice everything about Suzume. He also has a gentle and caring side to him that he rarely shows to others. Yuyuka has a crush on him.
