Because their fathers were good friends, the cheerful and rough teenagers Shuduomura Guang (voiced by Irino Miyu) and Tsukishima Wakaba (voiced by Kanda Akemi) became childhood friends. They had a beautiful promise to use Koshien as the stage. Unexpectedly, at the age of 11, Wakaba unfortunately fell into the water and died. In grief, Guang buried their dreams silently in her heart. As Wakaba's sister, Aoba (voiced by Tomatsu Haruka) felt several times more sadness than others, but she, who had been keen on baseball since she was a child, chose to grit her teeth and commemorate her sister's death with practical actions. In a blink of an eye, Guang was promoted to high school. In order to fulfill her dream with Wakaba, Guang joined the baseball team, but unexpectedly was assigned to the useless "fertilizer group". The next year, Aoba was admitted to the same school. Encouraged by Aoba, Guang and his teammates began rigorous training with Koshien as the ultimate goal. As long as we don't give up baseball, we can be together forever. As long as we can get together, the four-leaf clover representing happiness that is waiting silently in the corner will definitely be discovered one day.