The prodigious setter Kimichika Haijima returns to Fukui from Tokyo after an incident in his school"s volleyball squad forces him to leave. There he reunites with childhood friend Yuni Kuroba, a player on Monshiro Middle School"s boys" volleyball team who has yet to recognize his own gifts. Haijima spots Kuroba"s talent and resolves to assemble a new squad with him as the ace. During the prefectural tournament, Kuroba falters under pressure, leading Monshiro to collapse after a defeat. The loss also strains the bond between Haijima and Kuroba, prompting the former to abandon the team.
Now attending Seiin High School, Haijima and Kuroba find themselves teammates once more. Learning from past errors, Haijima guides Kuroba past his performance anxiety so he can become the ace and steer the team toward the prefectural finals. Supported by captain Shinichirou Oda and vice‑captain Misao Aoki, Seiin strives to win the prefecturals and earn Fukui"s spot at the Spring Tournament. The team also confronts internal challenges, balancing academic demands and personal rivalries, yet their shared resolve keeps them united. To achieve this, they must defeat Fukuho Technical High School, the current champions of Fukui. Will Haijima"s squad overcome the challenge, or will they repeat his earlier defeat?
