Takatsu Mutsuki is introduced as a scholarship pupil at a well-regarded academy, who apparently lacks any remarkable skill. Mutsuki commonly skips classes and indulges in gaming, but his fortunes change when Mizoguchi Taiga comes on board as a baseball player-transfer student. Taiga notes Mutsuki's resemblance to a rival pitcher and forces him to assume that role. Kanna, Mutsuki's sister, joins in, and they manage to enlist nine companions to establish a baseball team that embarks on various escapades.
