Aoba Tsukishima

The third daughter of the Tsukishima family, one year younger than Kou and Wakaba. Aoba is jealous of how much time Wakaba spends with Kou, and frequently tells Kou how much she hates him. She is an excellent pitcher, Kou modeling after her. She has a poster of Ryota Igarashi, a famous fastball pitcher, hanging on her bedroom wall, and says she is only interested in a guy who can pitch a fastball at 160 km/h (about 100 mph). She loves to pitch in practice games, even though as a girl she cannot play in official baseball. However, she rarely shows her real speed, as most catchers can't handle it. Her name means "blue leaf".

Upon entering high school, she has joined the baseball team, despite saying previously she would not.