Masumi Kurasuma

Masumi Kurasuma (烏丸 ますみ Kurasuma Masumi) is Sakuya's classmate and Sakuya and Isako's friends who helps out with sports clubs as a substitute player or practice partner, she is close friends with Eri but is not as perceptive as Eri is in reading the romantic moments Isako has for Sakuya.