Harumi Matsudaira, the younger brother of the famous Matsudaira brothers, whose fame in the sports world resonates throughout the country, has a shy and reserved personality, quite different from his brothers. Eager to change this aspect of his personality, Harumi decides to join the tennis club upon entering high school. Convinced that the same blood flows through his veins as his brothers, Harumi, with the support of those around him, gradually begins to develop his athletic talent. As his potential blossoms, he also begins to attract the attention of the girls around him. At the same time, his relationship with his childhood friend, Hanako Sakakibara, gradually evolves. The story follows the evolution of Harumi Matsudaira, determined to overcome his shyness and shine in the world of tennis while exploring aspects of his romantic life.