Just before entering junior high school, Harada meets Nagakura Go, a catcher of the same age. Nagakura is impressed with Harada's talent, and, hoping to form a pitcher-catcher battery with him, enrolls in the same local junior high school.

The story unfolds around the two boys' friendship and passion for baseball. Lots of interesting characters appear as the series progresses, sometimes hindering and at other times supporting the duo. These include Harada's family, the boys' teachers, and the boys and girls from their classes at school.