Mikawa is the astronomy club president. He's extremely passionate about space, so he was excited when Kobayashi and Uno joined. Only problem.. he has trouble talling, often scares people away, causing him to have a poor relationship with himself.

Uno is extremely expressive, and a space fanatic, but he forgets what to do in situations, so he keeps a book with him explaining routines he does, what to say in certain conversations, and how to act in certain situations. He loves spending time with Kobayashi.

Kobayashi's a delinquent who never used to focus in school because he never understood it. After meeting Uno he's started taking notes and trying out new things. He now keeps a book with him which he uses for his job so he doesn't forget what to do. He does stuff if it makes Uno happy, even learning what scares him to avoid I and learning his interests to keep him occupied with it.

Saku's a guy who's chill about everything, except not being able to tell how his best friend Kobayashi is feeling, what he's doing, or who he's spending time with. He doesn't want Kobayashi to change.