Sasameki Koto (TV Series)

Sumika Murasame is deeply in love with her cheerful classmate and friend Ushio Kazama. Ushio is openly lesbian but... she's likes cute girls, and Sumika, top student, class representative, black belt in karate, is all but cute. Even worse, Sumika herself is terrified of endangering her friendship with Ushio and chooses to maintain the status quo, as much as it pains her to hide her feelings...