Kunimi Akira.

Kunimi Akira and Kageyama Tobio used to be on the same volleyball team. Back then, Kageyama was extremely harsh and abrupt with the team, forcing them to play at a pace that was almost impossible for his teammates. Kunimi was especially infuriated when Tobio told him to give it his all—a phrase that always irritated and enraged him.

After some time, Kunimi learns that Kageyama is now on the Karasuno team and thought that he had not changed at all after he was removed from the team.

But surprisingly, Kageyama had changed a lot during this time. He listened to others, tried to help rather than push the team, and, moreover, he learned to play as part of a team rather than single-handedly push his teammates along.

On the same day, Aoba-Johsai and Karasuno agreed to train together during the summer holidays, so this is a chance for Kunimi to observe Tobio and his 'changes' even more.