Unit: knights

Age: 18

Birthday: September 22

Club: Tea Club

Ritsu always sounds sleepy and languid. Nocturnal and loves sleeping, he can be found napping anywhere. He had to repeat a year due to too much tardiness and dozing off in class, but he doesn't care.

Childhood friends with second year Mao Isara; they know each other very well. Even though he's older, Mao is actually the one taking care of him. Third year Rei Sakuma is his older brother, but he has a rather brusque attitude towards Rei. He hates getting involved with people.