A friend of hazumu she is his original crush. Originally she rejected him, but after he was turned into a girl she fell in love with her. She is part of the main love triangle and love playing the flute. She is incapable of physically seeing men.
During the events of Kashimashi ~Girl Meets Girl~, Yasuna turns down the male Hazumu Osaragi early on, only later to fall in love with the new famale Hazumu. Constantly competing with Tomari Kurusu, for Hazumu's affection.
She has androphobia, which is so severe, that she cannot even visually recognize male humans.