Sari Tokiwa 常盤沙里

Naru, Yaya, and Hana's homeroom and English teacher and Machi's older sister, who is often nicknamed 'Sally-sensei'. She originally planned to take over her parents' hospital together with Machi, but after helping Machi with studying, Sally chose to leave home, inspired to become a teacher instead. She becomes the yosakoi's club advisor, initially showing little interest but soon becoming more involved, including trying to make the girls wear cosplay while performing, though she is occasionally shown to be lazy and forgetful.