Kiryuu Usako

Miina's second childhood friend. She accepts Yuusaku as Miina's boyfriend more easily than Myuu. Because her name "usako" can be a cute way to address rabbits and rabbits are weak she tries to use bears as a way to change her image.

Spoiler

When she moves in with Miina and Yuusaku she begins treating Yuusaku as an older brother and calls him Onii-chan for a short time.