Aoba Tsukishima is the third daughter of the Tsukishima family. She is 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, and Kou models his pitching after hers. She has a poster of Ryota Igarashi, a famous fastball pitcher, hanging on her bedroom wall. She 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."