Saiki Kusuo[]
Hairo is the class representative of Kusuo's class. He is a hot-blooded young man who is reliable and gets along well with everyone, even towards the outcasts like Kusuo and his circle of friends. Though Kusuo at first finds Hairo overbearing and is annoyed by his wild nature, he respects Hairo’s strong will and how well liked he is in school, and he gets somewhat used to Hairo over time.
Shun Kaidou[]
Even though Hairo generally gets along well with everyone in his class, including outcasts, his relationship with Kaidou is questionable. Hairo has little confidence in Kaidou during Sports Day and simply tells him "just do whatever you gotta do" as he breaks a sweat. He lies to Kaidou, telling him that the class is still waiting for him and his friends in the restaurant Todoroki when in reality the rest of the class is partying without them, which greatly dismays Kaidou and Nendou when they find out. Hairo also has little belief in Kaidou’s sense of direction.
Nendou Riki[]
Nendou is a rival for Hairo in terms of sports and strengths. Nendou is usually lax in terms of Physical Education, but Nendou usually wins when Hairo challenges him in sports.
Kuboyasu Aren[]
When they first meet, Hairo treats Aren with his usual kindness. Though he notes Hairo’s popularity, Aren is at first put off by Hairo’s energetic nature and decides it is best to avoid him. However, when other classmates talk critically about Aren, Hairo stands up for him and says words which sound like something Aren's old leader would say. This causes Aren to respect Hairo and want to be friends with him.