Kō Kitamura, whose family owns a sporting goods store, has known the Tsukishima girls since he was born. The Tsukishima family runs a batting center and cafe, and they have four daughters. There's Ichiyo, the responsible eldest; Wakaba, Kō's cheerful best friend; Aoba, who doesn't get along with Kō; and Momiji, the energetic youngest daughter. When Kō enters high school, he aspires to lead his baseball team to the Koshien National High School Championship as their ace pitcher and make Wakaba's dream come true.
Twin brothers, Tatsuya and Kazuya, grew up with their next door neighbor Minami like siblings. Minami's dream is that her school's baseball team will participate in the national Koshien High School Baseball Tournament. The twin brothers make a pact that they will take Minami to the tournament.
Because of the legend left by Tatsuya Uesugi, Meisei Academy High School was well-known for their strong baseball team. But 26 years after their glory, the team has not been able to keep their record and has since lost their fame. Two stepbrothers, Souichirou and Touma Tachibana, aim to revive of the once-strong Meisei Academy baseball team and enter the National High School Baseball Championship. Souichirou and Touma are second years in Meisei Academy Middle School. Both boys are talented baseball players. Souichirou has shown excellent skill as a catcher and batter. Though having an extraordinary skill as a pitcher, Touma no longer pitches due to a certain reason. Once the two enter high school, they pair as a battery and aim to enter the National High School Baseball Championship!
