The third daughter of the Tsukishima family, one year younger than Kō and Wakaba. Aoba is jealous of how much time Wakaba spends with Kō, and frequently tells Kō how much she hates him. She is an excellent pitcher, Kō 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."