Episode 39

Watching a summer broadcast about All Might at the hideout, which Kurogiri kills almost at once, Tomura says he has worked out why Izuku Midoriya and the Hero Killer grate on him so badly: All Might hands the world a sense of hope through his deeds and his smile. He walks out resolved to build a world without the man and to show society how fragile its justice really is.

Izuku keeps training in his apartment, still finding it unreal that All Might's power runs through him, until Denki and Minoru turn up at his door proposing the school pool before camp starts. At U.A., Shota and Vlad King are reviewing the Quirks of Classes 1-A and 1-B when the three boys arrive to ask permission, which Shota grants.

The invitation was never innocent. The pair had eavesdropped while the girls arranged a pool day of their own, Class 1-A being barred from taking vacations, and brought Izuku along purely to secure permission. Izuku promptly invited every boy in the class for endurance work, and the girls turn up in school-issued swimsuits, disappointing Denki and only mildly satisfying Minoru.

Tenya drives the boys through endurance drills while the girls play volleyball, and during a break he and Izuku reflect on how their friendship came about. Eijiro and Katsuki arrive, Katsuki demands a fight, Izuku declines, and Tenya converts the challenge into a fifty-meter race. Most entrants use their Quirks instead of actually swimming. Izuku swims and still beats Tenya's Recipro Burst. Noticing Shoto afterward, the three renew their vows about the heroes they mean to become.

All Might meets Detective Tsukauchi to discuss recent League activity. The deciding heat, Izuku against Katsuki and Shoto, never happens, because Shota clears the pool the instant their allotted time expires. Walking home, Katsuki tells Eijiro he is furious about the interruption because he will never let those two beat him. At Takoba Municipal Beach Park, All Might tells his student to push himself at the forest lodge, since the role of Symbol of Peace may one day fall to him.

After dark, Vlad King and Shota talk over relocating the training camp to keep the students safe, while Tomura phones someone to say a new game is about to begin.

Almost the whole episode is anime-original, built loosely around part of Chapter 49.5 and material carried over from the first two seasons. U.A.'s records list Izuku's Quirk as "Super-Power", since only a handful of people know what One For All actually is.