Tomoki is Tomoko's younger brother. He often does not understand his sister and is bewildered and irritated by her odd behavior. Tomoko occasionally comes to him for advice. He later enters the same high school as Tomoko. Tomoki is very reserved and distant, even with his family and friends. Despite this, he appears popular in his class and admired by several girls. Tomoki has messy black hair and dark bags under his eyes like his sister. However, unlike Tomoko, he is considered attractive.