Akahoshi Corona

Luna's twin younger sister. Romantically loves her brother and doesn't make much effort to hide. She is a genius and she herself made the car that the group uses to go to school. Just like Luna and Lamune, drinks ramune everyday.

She's recently started thinking about happiness and decided that just being together with her friends and brother is "enough". Now she wants her friends to live happy lives and so invites her brother to make everyone happy.

Knows that Lamune, Iris and Rayla love Luna, but she isn't jealous. In fact she says she's waiting for someone to make her advance so everyone can have their share of Luna as otherwise Luna would be too much embarrassed to agree to do anything more, specially with his twin sister.