Episode 7

Deku vs. Kacchan (デクかっちゃん) is the seventh episode of the My Hero Academia anime.

Summary
"Deku" and "Kacchan" grew up in the same neighborhood and have known each other since they were little kids. Katsuki always felt superior to Midoriya, especially after developing his quirk. However, Midoriya still never treated Katsuki like he was better, and even tried to help Katsuki after he fell into a river. Katsuki only took this as an insult, like Midoriya was looking down on him. That same anger has carried over years later into the Battle Trial.

No longer children, Izuku refuses to allow Katsuki to bully him any longer and shouts the defiant words that he won't back down any longer. Katsuki is interrupted by a message from Tenya, asking for a status update. An angry Katsuki only tells him to defend the weapon before silencing his communication. Back on the offensive, Katsuki goes for a flying kick to Izuku's head but is countered by Izuku's hero knowledge once again. By using capture tape and the notes he took on both Katsuki and Eraserhead, Izuku is able to dodge.

Uraraka goes off to track down the hidden weapon while Izuku runs and hides from Katsuki to gain enough distance to form a plan. While searching for Izuku, Katsuki recalls their past and is enraged by the thought that Izuku believes Katsuki is weak like him. Meanwhile, Ochaco reaches the hidden weapon with Tenya guarding it closely. She finds Tenya getting into villainous character and accidentally reveals herself after laughing at him. Prepared for Ochaco's quirk, Tenya has already removed all the items in the room, giving her no weapons to use against him. Izuku contacts Ochaco and asks her where she is, to which she replies that she has found Tenya on the fifth floor. Izuku realizes that Katsuki must have gone rogue and left Tenya alone, and formulates a strategy to capture Katsuki and take Tenya two on one later.

Katsuki finally catches up to Izuku and questions why he won't use his quirk. He warns Izuku not to underestimate him and reveals the gauntlets on his hero costume stores his nitro-sweat. When enough of it builds up, he can create a massive explosion. All Might warns Katsuki not to use the attack, but he does so anyway and blasts through the far wall of the building.

Tenya and Ochaco feel the aftershock of the blast. Ochaco uses the moment to make herself float towards the weapon, but Tenya's speed allows him to keep it from her. Without anything to use as weapons, Ochaco is a step behind Ida, who can easily use his speed to keep the weapon from her. Meanwhile, All Might warns Katsuki not to use that attack again or else his team will lose. This forces Katsuki to resort to close range combat. Izuku tries to fight back, but in close quarters, Katsuki proves that he is far stronger. He uses his explosions to change trajectory in the air and blast Izuku from behind. Then he grabs onto Izuku's arm and slams him into the ground after using explosions from his free hand to build up momentum. Katsuki's fighting prowess garners him praise from the class, who are surprised how the tide has turned against Izuku.

Katsuki once again demands that Izuku use his quirk, questioning whether Izuku feels he's too good for that now. This irritates Izuku, who expresses that he has always felt Katsuki is better, and that's why he wants to beat him. Filled with emotion, both fighters rush each other for a final clash. Knowing he can't defeat Katsuki at close range, Izuku uses One For All to smash the ceilings from every floor of the building. This smash creates enough debris for Ochaco to use on the floor above. She uses her Quirk to float debris and sends them flying at Tenya, then uses the opening to grab the weapon and secure the victory for Team A.

On the floors below, Katsuki is shocked to learn that his explosion severely injured Izuku. The latter left himself open because it was the only way he could win the match, conceding to Katsuki's incredible talent. Despite his dominance, Katsuki has lost the match to Izuku.