After the victory against Aoba Johsai High, Karasuno High School, once called "a fallen powerhouse, a crow that can't fly," has finally reached the climax of the heated Spring tournament. Now, to advance to nationals, the Karasuno team has to defeat the powerhouse Shiratorizawa Academy. Karasuno's greatest hurdle is their adversary's ace, Wakatoshi Ushijima, the number one player in the Miyagi Prefecture, and one of the country's top three aces. Only the strongest team will make it to the national tournament. Since this match is the third-year players' last chance to qualify for nationals, Karasuno has to use everything they learned during the training camp and prior matches to attain victory. Filled with restlessness and excitement, both teams are determined to come out on top in the third season of Haikyu!!.

After losing against Aoba Johsai, the whole Karasuno team feels at a loss. Especially Kageyama and Hinata, who seem to be the most devastated about the defeat. However, the team soon cheers up when a chance for them to go to Tokyo appears. During their training camp there, Karasuno will meet new formidable opponents.

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.

A chance event triggered Shouyou Hinata's love for volleyball. His club had no members, but somehow persevered and finally made it into its very first and final regular match of middle school, where it was steamrolled by Tobio Kageyama, a superstar player known as "King of the Court." Vowing revenge, Hinata applied to the Karasuno High School volleyball club... only to come face-to-face with his hated rival, Kageyama!

Haruka, who is attending college in Tokyo, meets Asahi again and reawakens his memories from his middle school years, including those of Ikuya. Makoto is working toward a new dream while he is in Tokyo together with Haruka. Rin has an unexpected meeting in Sydney.

The Iwatobi Swimming Club is back and struggles with the recruitment of new members. At the same time, senior members Haru and Makoto have to figure out what to do after high school, challenging their love for swimming. Meanwhile an old childhood friend of Rin returns and stirs up some trouble - especially with Haru. How is the Iwatobi gang going to respond?!

Four boys named Haruka, Makoto, Nagisa and Rin all participated in a swimming tournament shortly before graduating elementary school and later parted ways. Years later, they reunite when Rin challenges Haruka to a race and wins. Not wanting to be defeated so easily, Haruka gathers Makoto and Nagisa and a new recruit named Rei to form the Iwatobi High School Swimming Club.