Izuku Midoriya & Ochaco Uraraka vs. Katsuki Bakugo & Tenya Ida

Izuku Midoriya & Ochaco Uraraka vs. Katsuki Bakugo & Tenya Ida also known as Deku vs. Kacchan is a battle fought between U.A. Students Izuku Midoriya and Ochaco Uraraka (Team A) against Katsuki Bakugo and Tenya Ida (Team D) during the Battle Trial.

Prologue
All Might uses Class 1-A's first Foundational Hero Studies session for combat training. The students change into their hero costumes and meet him at Ground Beta. There he explains that he is moving the students two steps ahead of the urban battles they participated in during the Entrance Exams by pairing them up for indoor battles.

All Might explains the situation is as follows: the villains are hiding a payload inside the building and the heroes must secure it or defeat the villains within a time limit. The villains are granted victory if they successfully protect the payload or capture the heroes. As proof that an opponent has been captured, they have to wrap a Capture Tape around them.

The students are paired up based on chance by drawing lots. Izuku and Ochaco end up together on Team A. While Katsuki and Tenya are paired on Team D. Izuku is nervous about being paired up with a girl like Ochaco and hopes to make a good impression on her. All Might selects the first two teams to fight at random, and it ends up being Team A as the heroes with Team D as the villains. Izuku glances over at Katsuki and fearfully looks away once he notices Katsuki is scowling back.

Shortly after, Izuku finds his resolve and looks Katsuki back in the eyes, angering the latter. Team D is instructed to go inside the replica building. There, Tenya and Katsuki discuss Izuku's Quirk. Tenya questions why Katsuki is so angry with Izuku but gets no reply. Thinking that Izuku had been fooling him all this time about being Quirkless, Katsuki silently prepares himself to fight against his former friend.

Meanwhile, Ochaco notices Izuku sweating through his costume. Izuku nervously explains that Katsuki is extremely talented and his attributes are superior to Izuku's own. Izuku goes on to state that he must improve and will win the Battle Trial. Ochaco asks if their battle is fated and Izuku apologizes for getting her wrapped up in his rivalry. She dismisses this and encourages their team to win.

All Might announces the start of the round

Battle
Izuku and Ochaco infiltrate the building where the exercise is being held without problems, walking the corridors for a while, always in high alert to any surprise attack from the rival team. Izuku is worried about not being able to control the OFA yet, fearing that he could kill someone if he used it again, so he will reserve it as a last resort, facing any unforeseen using his head and Ochaco's abilities.

Katsuki suddenly ambushes them emerging from an adjoining corridor, ready to blast Izuku. His sneak attack only manages to damage half of Izuku's mask, the latter was able to swiftly dodge while moving Ochaco out of the way. Katsuki expresses how he will injure Izuku to the point where the battle is stopped, just close, and follows up with another attack, but Izuku is able to counter. Grabbing Katsuki's arm, Izuku slams him to the ground. Katsuki is astonished that he was able to read his move.

Izuku had taken notes on Katsuki in the same hero notebook the latter had burned and tossed out the window. Using his notes, Izuku was able to predict that Katsuki's opening move would be a right hook. He firmly states to Katsuki that Deku is the name of a hero, no longer the defenseless boy from their childhood. Katsuki is enraged that Izuku, despite being scared, wants to fight him anyway, and vehemently says that’s why he hates him.

Tenya contacts Katsuki asking for a status update, since he went off on his own, but Katsuki aggressively tells him to shut up and keep guarding the bomb, because in those moments he is really pissed off. Tenya tries to reply him, but Katsuki cuts off the communication. Tenya feels annoyed by Katsuki's behavior.

Since Katsuki is so focused on attacking him, Izuku tells Ochaco to use the chance to get away and try to reach the payload. Katsuki uses his explosion to propel himself and attacks again with a kick, but Izuku is able to block the attacking and attempts to use the Capture Tape, but Katsuki unleashed another right hook explosion, which Izuku successfully dodges. Izuku quickly retreats to make a plan, severely irritating Katsuki, who angrily expresses his belief that Izuku was tricking him for years by pretending to be weak.

While hiding from Katsuki, Izuku begins to formulate a strategy. Izuku can’t join Ochaco at the moment since Katsuki would follow behind him, and he can’t take too long dealing with Katsuki either since that would make Izuku's team run out of time. So Izuku settles on capturing Katsuki quickly before joining Ochaco against Tenya and claiming victory.

As Katsuki searches for Izuku, he thinks to himself as to how Izuku was just a bug he can squash, before remembering from their childhood how he fell into a river and Izuku tried to help him. Unfortunately, Katsuki took this as gesture as an insult, believing Izuku saw him as a weakling that needed help, and an infuriated Katsuki says that he is much better than Izuku.

Meanwhile, Ochaco reaches the room where the fake bomb is, with Tenya guarding it. Tenya tries his hardest to get into villainous character, taking his villain role so seriously that Ochaco can't help but laugh, causing her to reveal her position. Tenya informs Ochaco he is prepared to counter her Quirk by removing everything from the room other than the payload. Ochaco informs Izuku of the bad news, but he has enough to deal with as Katsuki finds him.

Katsuki taunts Izuku by asking him to use his power rather than hiding it. Then he brings up the notes Izuku has taken on his Explosion Quirk. Katsuki reveals that the gauntlets on his hero costume store his nitro-sweat, and can release it all at once with a huge blast. Despite All Might's warning, Katsuki shoots it at Izuku, saying it won’t hit Izuku as long as he dodges. Izuku narrowly dodges the blast that destroys a large portion of the building.

Katsuki walks over to Izuku telling him how his gauntlet can release bigger explosions the more nitro-sweat he stores in them. Smiling sinisterly, Katsuki claims Izuku will never beat him, no matter what power Izuku has. Tenya and Ochaco both feel the explosion. Ochaco tries to use it as an opening to grab the weapon Tenya is protecting. She floats herself and makes a jump to avoid Tenya, but he is too fast for her and uses his Engine Quirk to keep the bomb out of her reach.

All Might warns Katsuki not to fire another blast or his team will lose automatically. Irritated, Katsuki adjusts and moves into close-quarters combat with Izuku. He tries to fight back, but Katsuki completely dominates in close combat. He uses his explosions charging forward where he gets in the air using his explosions which leads him to changing his trajectory in a blast that doubles as a smokescreen which finally causes him to blasting 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, and calls Izuku a weakling.

Katsuki's fighting style garners him praise from the class, who are surprised how the tide has turned against Izuku, but secondly his peers and All Might note his tendency to go too far as well as act like a villain.

Katsuki once again demands that Izuku use his quirk, questioning whether Izuku feels he is superior now that he is no longer Quirkless. This irritates Izuku, who expresses that he has always felt Katsuki was superior, and that is why he wants to beat him. Filled with emotion, both fighters rush each other for a final clash as Izuku uses his Quirk which delights Katsuki as he moves to attack.

Knowing he cannot defeat Katsuki at close range, Izuku alerts Ochaco to grab onto something. Instead of punching Katsuki, Izuku aims his Detroit Smash into the ceiling, destroying the ground of every floor above them, including the one Ochaco and Tenya are on, but Izuku is forced to take the full brunt of Katsuki's Explosion.

This smash creates enough debris for Ochaco to use on the floor above. She uses her Zero Gravity Quirk on the pillar she is grabbing onto to float it and uses it to bat enough shrapnel towards Iida, in a improvised Super Move she called "Comet Home Run". A dumbfounded Tenya asks how she can call that a "home run" before shielding himself from the projectiles. Caught in the onslaught of rubble, Tenya is unable to stop Ochaco from using her Quirk on herself again to jump the hole in the ground, grabbing the weapon and securing the victory for Team A.

Aftermath
Katsuki is shaken by the loss and berates Izuku for deceiving him. Izuku corrects him, saying that the only desperate plan he could come up with in time to defeat Katsuki. When the smoke clears, Katsuki is shocked to see that he has severely injured Izuku. In the monitoring room, the rest of Class 1-A also watches in horror of Izuku's injuries. All Might confirms the hero team's victory as Izuku slowly passes out from the pain.

Tenya checks on Ochaco's condition while Izuku is carried off to the nurse's office. Denki comments on the uncanny ending of the fight, noting that the heroes are injured while the villains are practically untouched. Katsuki is distraught over losing to Izuku and begins to hyperventilate over the thought of losing to Izuku again if they fought all-out, but All Might comforts him and brings all three remaining participants back to the viewing room.

All Might asks Class 1-A to critique the battle and announces that Tenya is the MVP of the exercise. Tsuyu says that one of the heroes should be honored since they won but All Might refutes that notion. Momo explains that Tenya was the only one who adapted to his role and the situation. The others did not respect the spirit of the trial and made impractical decisions throughout the fighting.