Ritsuka first comes across him sleeping alone on a stairway accepting his offer to sit beside him. He notices Mafuyu's rusted guitar strings and eventually relents to fixing them for him despite a pressing need to nap instead. He becomes a reluctant guitar teacher to Mafuyu. Ritsuka quickly realizes that Mafuyu is an exceptionally talented singer, and invites him to join the band. Mafuyu and Ritsuka started to develop feelings for each other.
He can be abrupt when guiding Mafuyu on account of his lack of patience, but adjusts when this behaviour is called out by others. Ritsuka considers Mafuyu hard to understand but always puts in the effort to meet the bands expectations. He expressed shock at Mafuyu breaking his guitar strings remembering how much it meant to him that they could be fixed, and feels he is responsible since he was the one who suggested Mafuyu sing.
A college student and member of Ritsuka's band where Akihiko plays the drums. Ritsuka describes him as scary looking but a nice guy. He knows he is a second-year student at the same college Haruki goes to.
His elder sister who he grew up with when in the sixth grade she flatly told him his guitar playing sucks. They are close as brother and sister, Yayoi enters his room of her own will to hurl his boxers that were mixed with her laundry. She responds to his opinion that she was dumped by Kaji, by throwing a bottle filled with liquid at him.
A classmate who encourages Ritsuka to take part in activities be it buying bread during their breaks at school or playing basketball. Ritsuka is questioned on his new friend in Mafuyu with them both described by Shogo as not very sociable. They are friendly overall and play basketball together.
Ritsuka and Hiiragi perform together when Hiiragi's band needed a guitarist. They often end up arguing about little things and yell at each other as Yagi is sitting silently by the drums looking at the two fighting. Ritsuka observes Hiiragi's performances playing music and envy him for his act of being extrovert and cool in public.