Koichi Kawato, a 24-year-old single man, is an enthusiastic teacher specializing in modern Japanese. He has been accepted at Futagotamagawa Gakuen High School and assigned to class 1-B. Unbeknownst to him, all members of the baseball club are in this class, having earned a delinquent reputation following their expulsion from both school and tournaments.
Throughout the series, Kawato's honest and positive demeanor stands out as he consistently faces adversity yet remains resilient and optimistic. These unique qualities of Kawato gradually influence not only the titular "Rookies" for the better but also his colleagues, many of whom had previously believed that delinquents were beyond help.
