Mino[]
According to Mino, the two of them share a uniquely friendly sibling relationship. This is primarily due to the fact that their parents are rarely at home and they have to help each other out. As kids, Mino recalls the two of them playing together a lot, especially his 'favourite game', which involved her picking him up from behind and whirling him around by his arms. Motoharu, however, remembers it as her way of bullying him.
The two usually walk home together, during which Mino invariably asks him what he wants for dinner and strikes up a conversation with him. They are well aware of how ‘normal’ their interactions are compared to their friends’ siblings. Despite this, Motoharu is occasionally on the receiving end of things, since his sister likes to wield her seniority over him. She does not intervene when her friends turn bullies and force him to quote silly comedians and put his hair into ponytails. She also spreads lies about him to them and is jealous of his cooking prowess.
Karasawa[]
The two are classmates and good friends. As student council members, they share a sense of responsibility and strict work ethic, but are not above goofing off once in a while. They hang out outside school as well (sometimes with other council members), and are even seen having make-believe adventures of their own.
Along with the Vice President, they are often seen tolerating Ringo’s antics or amusing themselves by pranking her.
Yoshitake[]
Motoharu went to the same elementary school as Yoshitake and they sometimes walk home together in high school. Motoharu interacts with Yoshitake the most out of the main trio.
He tries to prank Yoshitake once by sending him a fake love letter, but chickens out and shifts the blame when he sees how riled up he gets. Motoharu also witnesses his ability to lie impressively on different occasions. The two share an emotional moment of friendship when Yoshitake teaches Motoharu to successfully ride a cycle within one evening, in the aftermath of having his purse snatched.
Mitsuo[]
Motoharu is friends with Mitsuo, and the two sometimes walk home together from school. As kids, Motoharu used to pull pranks on him such as switching his shoes with a girl’s. He continues to pull pranks on him even in high school, such as making him take the fall for sending Yoshitake a love letter. However, Motoharu is always shown to feel guilty after these instances.
He does care for Mitsuo, once going out of his way to save his food from falling down. He also took part in the plan to get Mitsuo a new robot model as a birthday gift.
Other[]
Motoharu’s other interactions include goofing around with the main trio, chatting with Megane and Chapatsu, talking to the Vice President and putting up with Ringo when she comes over to North High. He’s also helped out Tadakuni’s younger sister on a couple of occasions.