Minami Shinichi is an unusual boy. He doesn't go to school and lives in a tenement house. There, a mysterious old man calls Shinichi "Young Master" and teaches him difficult subjects every day. What surprised the boys on the baseball team at the nearby Y High School the most was that Shinichi turned down a scouting offer from the Giants and started a baseball team called the "Young Giants". Shinichi threw down a letter of challenge to the Y High School baseball team, who looked down on the weak team!!