Episode 7

Deku and Kacchan share a hometown and a history stretching back to early childhood. Once his Quirk emerged, Katsuki assumed superiority as a matter of course, and Izuku's refusal to treat him that way stung. Even a hand offered after Katsuki tumbled into a river registered as condescension. That old grudge is what surfaces during the Battle Trial.

Standing his ground for once, Izuku declares he is finished being pushed around. Tenya interrupts by radio asking for a status report and gets snapped at to guard the weapon before the line goes dead. Katsuki launches a flying kick at Izuku's head, and Izuku slips it, drawing on capture tape and the notebooks he keeps on both his rival and Eraser Head.

Ochaco splits off to find the payload while Izuku puts distance between himself and Katsuki to think. Hunting him, Katsuki stews over the idea that Izuku sees him as weak. Upstairs, Ochaco discovers Tenya hamming up his villain role and gives herself away by laughing. He has stripped the room bare, leaving her Quirk nothing to lift. Her report that Tenya is alone on the fifth floor tells Izuku that Katsuki abandoned his post, and a plan forms: capture him, then take Tenya two on one.

Cornered at last, Katsuki demands to know why the Quirk stays unused and warns against underestimating him. His gauntlets have been banking nitro-sweat for exactly this, and despite All Might's warning he fires, blowing out a far wall. The shock reaches the floor above, where Ochaco floats toward the weapon only for Tenya's speed to keep it away from her. Told another blast will cost his team the match, Katsuki closes to fists, and up close he is simply better, redirecting himself midair with explosions, striking from behind, then hauling Izuku by the arm and driving him into the floor. The watching class is startled by how thoroughly the fight has turned.

Pressed again about the Quirk, Izuku snaps back that he has always thought Katsuki was the better of them, and that is precisely why he wants to win. Both charge for a last collision. Unable to match him at that range, Izuku aims One For All at the ceiling, and a Detroit Smash rips through every floor above. The debris it throws up gives Ochaco her weapons: she floats the rubble, hurls it at Tenya, and seizes the payload for Team A.

Below, Katsuki learns his blast wrecked the left arm Izuku raised to block it, a deliberate cost accepted because it was the only route to victory, an admission of just how far Katsuki's talent reaches. He controlled the fight from start to finish and lost anyway.

The childhood history between Izuku and Katsuki is laid out, including the riverbank incident that Katsuki took as pity.

Katsuki's Grenade Gauntlets and stored nitro-sweat are introduced, and All Might penalises him for firing them recklessly.

Izuku wins with an upward Detroit Smash that shreds the building, letting Ochaco use Comet Home Run to take the weapon and hand Team A the match.

The seventh episode of the series, adapting Chapter 9 and Chapter 10 during the Battle Trial arc.

The anime visualises Izuku's full strategy and stretches the childhood flashbacks and the buildup to the final clash, while dropping the manga's map of the fifth floor.

Shoto delivers the observation about Katsuki being smarter than he looks, a line given to Momo in the source, and Ochaco secures the fake weapon before the two boys speak rather than after.