The students of Class 1-A are separated into groups of two, heroes versus villains style. They are judged on how well they would do at being heroes.
All Might sets the entire class into 10 groups for an exercise in which one group will play villains while another play heroes. Bakugo is still angry at Midoriya for thinking he was lying about being quirkless for years and as luck would have it, the team formed by Midoriya and Uraraka will face off against the "villain" team made by Bakugo and Ida.
The point of the exercise is for the heroes to get into a building and try to either contain the villains or retrieve a bomb they have hidden in the building.
Midoriya comes up with a plan where he'll distract Bakugo in order to let Uraraka get to the bomb, knowing that in an all out fight, they have the disadvantage against the other more powerful team. Bakugo and Midoriya have a large scale fight in the corridors, with Midoriya avoiding using his quirk to not break his bones while Uraraka finds the room where Ida is keeping the bomb and acting like a super villain.
Bakugo becomes infuriated enough to use a huge blast of his power that could destroy the building. All Might almost calls the exercise off, but Midoriya ends up using his full quirk to destroy the building upwards, crushing the room where Uraraka and Ida are fighting, allowing Uraraka to use her anti gravity powers to recover the bomb.
Midoriya is led to the infirmary. The rest of the team is lectured by Yaoyorozu on why they failed in many ways except Ida. Bakugo watches the other battles.
After Midoriya recovers and meets with All Might, he runs after Bakugo, revealing about the fact he was quirkless, but has received a quirk from someone else. Bakugo starts crying and does not believe him, having his pride stepped on not only by losing to Midoriya but also by seeing people like Yaoyorozu and Todoroki out-do him easily. He goes off swearing to fight with him again.
Tropes
- Always Someone Better: Not only is Bakugo's ego left bruised after Midoriya manages to win the challenge with his Quirk but he then sees Shoto Todoroki casually defeat his opponents by freezing them, and the entire building in its place, giving his team an easy win without compromising the conditions of the trial, leaving Bakugo to realize he wouldn't be able to defeat him in a one-on-one fight.
- Break the Haughty: Bakugo gets served with a giant piece of Humble Pie by the end of this arc. Intending to get revenge on Midoriya for supposedly lying to him about being Quirkless he is instead taken to task by him, first having his moves predicted by his former friend, and then losing the match when Midoriya blows the roof of the building their in away with his Quirk, leading him to the conclusion that if they fought without trial conditions Midoriya would win. This is compounded by having Momo Yaoyorozu succinctly pointing out all of the flaws he demonstrated during the exercise (which he later acknowledges) and seeing Shoto Todoroki completely mop the floor with his opposing team without damaging the building they were in. This leads him to realize that he is just a Normal Fish in a Tiny Pond now that he is in UA and leaves him in frustrated tears before telling Midoriya that he will get stronger and beat him.
- Cassandra Truth: After the trial is over Midoriya runs up to Bakugo and tries to explain to him that he wasn't tricking him since they were kids and that his Quirk is something he only just recently inherited from someone else and not something he has full control over yet. Bakugo doesn't buy that, while being frustrated that he's not so special after all, noting that he lost and vows to not let Midoriya beat him again.
- Conveniently Empty Building: Averted; the U.A. kids are taught from the very beginning to avoid property damage whenever possible because this trope isn't in play. As such, both Bakugo and Midoriya lose standing in the results for firing off massive blasts while fighting indoors. All Might states that even villains are aware of this.
- Curb-Stomp Battle: Todoroki gives one to Ojiro and Hagakure by completely freezing the building they are in to stop their movements and then casually walking up to the bomb and touching it.
- David vs. Goliath: Midoriya against Bakugo. Midoriya is used to quivering against Bakugo but in the training exercise finally stands his ground. Unfortunately as Bakugo has years of practice with his Quirk he demonstrates that Midoriya had good reason to be afraid of since with a dangerous Quirk he just acquired, Midoriya can't beat him. Midoriya realizes this however and does managed to come up with a plan to win the training exercise even if he can't win against Bakugo.
- Godzilla Threshold: Midoriya at the beginning of the trial tries to avoid using his Quirk and instead use his knowledge of Bakugo to capture him. However not only does Bakugo prove to be too strong to defeat without his Quirk but with time running out he doesn't have time to come up with a better plan. Therefore he decides to utilize an all or nothing gambit by using One For All to blow the roof of the building away counting on Uraraka to handle grabbing the weapon at the cost of the backlash messing up his arm.
- Hero Antagonist: Bakugo is the primary antagonist of the arc, with much of it being devoted to his and Midoriya's past and their budding rivalry.
- Leeroy Jenkins: The trope could also be named 'Katsuki Bakugo' if Leeroy hadn't got there first. Bakugo, still suffering from his middle school Normal Fish in a Tiny Pond problems, rushes off to fight Midoriya. Not only does Midoriya fight him evenly, he ends up tricking Bakugo to give Uraraka a chance to get past Ida- which would never have worked if Bakugo had actually stayed with Ida like he was supposed to. To add insult to injury, Todoroki also tries completing the exercise without the aid of his partner- and he wins handily.
- Pyrrhic Victory: The Heroes vs. Villains training exercise ends up as this for Midoriya and Uraraka — although they won by the conditions of the exercise, Ida and Bakugo were practically uninjured (except for Bakugo's pride) while Uraraka ended up heavily nauseous and Midoriya was straight-up hospitalized. This is acknowledged in-universe.
- Saying Too Much: Midoriya is supposed to keep One For All a secret, but he instinctively confesses to Bakugo about it and plans to make the given power his own. Though he catches himself too late, Bakugo is too frustrated to listen, much less believe him. All Might later chastises Midoriya since, while One For All can only be surrendered willingly, the wrong person with that knowledge can force him to do so.
- Took a Level in Badass: Midoriya stands up to Bakugo during the exercise, and vows to give the "Deku" insult he has endured over the years a more heroic meaning thanks to Uraraka.
