Boku no Hero Academia: Training of the Dead

OVA bundled with the 14th manga volume.

Story about a joint practice session between Izuku's class and Isami High students at Yuuei Academy, takes place after the field training arc in the second season.

(Source: MAL)

Boku no Hero Academia 2

Taking off right after the last episode of the first season. The school is temporarily closed due to security. When U.A. restarts, it is announced that the highly anticipated School Sports Festival will soon be taking place. All classes: Hero, Support, General and Business will be participating. Tournaments all around will decide who is the top Hero in training.

(Source: Anime News Network)

Boku no Hero Academia: Training of the Dead Franchise