After their triumphant victory over Shiratorizawa Academy, the Karasuno High School volleyball team has earned their long-awaited ticket to nationals. As preparations begin, genius setter Tobio Kageyama is invited to the All-Japan Youth Training Camp to play alongside fellow nationally recognized players. Meanwhile, Kei Tsukishima is invited to a special rookie training camp for first-years within the Miyagi Prefecture. Not receiving any invitations himself, the enthusiastic Shouyou Hinata feels left behind.

However, Hinata does not back down. Transforming his frustration into self-motivation, he boldly decides to sneak himself into the same rookie training camp as Tsukishima. Even though Hinata only lands himself a job as the ball boy, he comes to see this as a golden opportunity. He begins to not only reflect on his skills as a volleyball player but also analyze the plethora of information available on the court and how he can apply it.