Hiromi Oka

A high school girl who struggles to become good at tennis. Hiromi starts playing tennis in her high school, Nishiko, because she is fascinated by an older girl, Reika Ryūzaki, who is the best player in the team and is nicknamed "Madame Butterfly" (お蝶夫人 ,"Ochōfujin"?) because of her grace on the tennis court. The team gets a new coach, Jin Munakata, who sees potential in her and trains her to become a great tennis player. Hiromi struggles to overcome her mental weakness. Nishiko is modeled after Urawanishi High School, from which the author graduated.

(Source: Wikipedia)