Shimamura Hougetsu is a high school student. She met Adachi while skipping class on the second floor of the gym in her school when Adachi accidentally walks in on her one day. (In both manga adaptations, it was Shimamura who walked in on Adachi in the gym when they first met instead of the reverse.) The two instantly took a liking for each other and began to hang out together all the time. Shimamura has tail-bone length, dyed brown hair, which she keeps out of her face with two clips on the right side. Her eyes are also brown. Despite playing basketball in middle school, Shimamura is on the shorter side. She has a slim figure. Shimamura tends to think of interpersonal relationships as bothersome since she feels that it requires too much effort to maintain a balanced relationship.

Spoiler

During a summer break in their second year of high school, Shimamura is confessed to by Adachi at a summer festival, and chooses to accept her feelings, thus becoming her girlfriend.