Coach Nakao leads the baseball team at Seishū High School, where his daughter Yuri serves as team manager. His position is threatened by the team's prolonged losing streak and lack of success prior to the series' events, creating pressure to secure victories and prevent the team's potential shutdown. Before coaching at Seishū, Nakao had a brief period coaching Kentarō Yamanaka, the star pitcher of rival school Bunan High School, during Kentarō's younger years; they were neighbors at that time. Decades earlier, Nakao formed a battery with Eiji Kurahashi's father, winning the invitational Kōshien tournament, Japan's prestigious high school baseball championship. He leverages this significant past connection to persuade Eiji Kurahashi's reluctant father to allow Eiji, a highly talented pitcher, to join Seishū. Eiji's addition becomes pivotal to the team's improvement and quest to reach Kōshien. Nakao focuses on guiding the team through its challenges, integrating new players like former track star Katsuya Niimi and judo champion Susumu Karasawa, and fostering their growth within baseball while navigating competitive pressures and the goal of reaching the national tournament.