Rin is the cousin sister of Reiji Oyama and a passionate high school girl whose aim in life is to be a strong karate woman. She has a calm and polite personality. She has been training with her uncle and Reiji since she was 4 years old. In order to become stronger, she has added the techniques of Okinawan Karate to those she has learned from them. After further years of training, she has gained enough confidence to participate for the first time in a Goketsuji Tournament, and begins to follow the way of the karate maiden.