Izuku Midoriya vs. Katsuki Bakugo

Izuku Midoriya vs. Katsuki Bakugo, also known as Deku vs. Kacchan 2, is a battle fought between childhood friends and longtime rivals Izuku Midoriya and Katsuki Bakugo.

Prologue
Class 1-A returns to Heights Alliance following the conclusion of the Provisional Hero License Exam. While everyone else unwinds from the exam, Katsuki walks past Izuku and calls him out. He tells Izuku to meet him out front later so they can have a talk about his Quirk.

They both leave the dorms in the middle of the night. Izuku is concerned about being out past their curfew, but Katsuki ignores him and leads them to Ground Beta. Katsuki mulls over their childhood together, remembering when Izuku used to fawn over Katsuki's Quirk. Katsuki reminds Izuku that Ground Beta is the same place where Izuku defeated him during the Battle Trial.

Katsuki expresses his true feelings toward Deku. He was always annoyed by Deku because he was Quirkless and weak. After the Battle Trial, Izuku told Katsuki about his borrowed power. Katsuki didn't believe him at the time, but Izuku always appeared to be satisfied with himself and started to become stronger and stronger. He didn't understand how Izuku kept getting stronger ever since All Might came to town. It’s culminated to the point where Izuku has passed the licensing exam while Katsuki failed. Izuku tries to explain that it's not a matter of skill, but Katsuki tells him to stop talking and to listen.

Katsuki admits that the Kamino Incident helped him understand. Izuku knows what's coming, Katsuki asks him if he got his Quirk from All Might. He made the connection that All For One and All Might know each other and both have the ability to pass on their Quirks. Izuku changed after he met All Might and All Might lost his powers. Izuku is also the only one to have an adverse reaction to All Might's televised last comment in Kamino. Katsuki already asked All Might about it, but he didn't answer and so Katsuki now asks Izuku.

Izuku knows this confrontation is a result of him not listening to All Might the first time he told Katsuki. Katsuki believes his theory to be true because Izuku doesn't deny any of it and remains mostly silent. Izuku asks what Katsuki is going to do with the answer. He replies that they both wanted to be like All Might but Izuku is the one who got acknowledged by him. Frustrated, Katsuki tells Izuku they need to fight right there right then.

Battle
Izuku tells Kacchan it's a bad idea to fight because they're already breaking the rules and says they should fight during a training class. Katsuki ignores Izuku's pleas and states that if they fought during a training session, the teachers would keep them from going all-out, and goes on to say that he wants to see for himself why All Might had chosen Izuku. Katsuki stretches his arms to prepare and warns Deku to put his guard up or else he might get hurt. He disregards this after remembering that Deku uses kicks now. Izuku continues to plead only to be met with Katsuki blasting himself into striking range.

Katsuki winds up his signature right hook. Izuku believes it's a feint because this is how he started in their last bout. Izuku overthinks his opponent's attack and nearly gets exploded. Izuku's leg is hurt even though he dodged at the last second. Katsuki warns him not to read into battle too much. He demands Deku fight back and jumps at him. While in mid-air, Izuku ducks under Katsuki before he adjusts and sends down explosions that blow up nearby buildings. Izuku manages to avoid the explosions and tells Katsuki that his aspirations to be like All Might weren't wrong. Katsuki launches himself into the air and quickly rockets himself straight for Izuku. Izuku manages to evade and continues to plead with his childhood friend to wait.

Deku was always under Kacchan during their childhood. No matter how much Kacchan rejected and belittled Izuku, he was always right behind him. Katsuki recalls this as he leaps at Izuku and the latter dodges the incoming explosion. Katsuki demands Izuku stop running and mulls about how he and Deku admired the same hero. Katsuki rushes Deku again and he's forced to stop the former by grabbing him. Katsuki delivers an uppercut kick and tries to capitalize with a two-handed explosion. Izuku uses the momentum from getting hit to bicycle kick Katsuki's hands away so his explosion detonates into the air. Katsuki falls back and Izuku rushes over to help him. Katsuki rejects Deku's hand, angrily telling him to not worry about him. As Katsuki wonders why Izuku won’t attack him, he rises to his feet, and breaks down asking why he ended up chasing behind Izuku who was always far behind him all their life. Emotional, Katsuki asks why did Deku get so strong and while he ended up causing the end of All Might's hero career.

Katsuki is being tortured by the thought of being too weak and the reason behind All Might's retirement. Izuku is sad to see that Kacchan has suffered even more than he has. This battle may seem meaningless, but Izuku must fight because he's the only one who can understand what Katsuki is going through. He understands that Katsuki needs to let out his bottled up feelings. Katsuki runs at him and gets hit in the face from Deku. Izuku is optimistic and believes this is a good chance to test out Shoot Style. He tells Kacchan that if they're going to fight then he's going all out and won't act like a punching bag.

This is the first time they've ever talked about their complicated relationship with one another and now they use the battle to communicate their feelings. Katsuki launches himself into the air and then quickly down at Deku. Izuku jumps back to avoid the explosion, but Katsuki transforms himself into an exploding pinwheel to close the distance. Izuku dodges his hand, causing Katsuki to miss. Katsuki bounces himself off the ground then uses more explosions to flank Deku and delivers a powerful punch to Deku's side that sends Deku flying into a nearby railing.

Katsuki doesn't give Deku any time to recover and leaps to the railing. Izuku dodges the initial explosion but Katsuki uses the momentum to spin himself around and grab him. He tosses Izuku away and falls into the rail himself. Izuku starts to recover and realizes that despite his tendency to read into things, his reaction time has improved considerably. Katsuki gets annoyed by Izuku's self-confidence and lunges at him with an explosion. Izuku evades and Katsuki states he's still acting like a sandbag. Izuku refutes this and runs at Kacchan. Katsuki deduces that Izuku has some sort of plan prepared, unleashes his Stun Grenade technique to blind Deku, and then punches him in the face while expressing his disdain with Deku's attitude.

Katsuki tries to follow up with a second explosion but Izuku leaps out of the way. Katsuki admits he can't get a read on Deku and believes he's always looking down on him. No matter how much Kacchan beat Deku up, he always stayed close behind him as if he were going to surpass him. Izuku is unpleasantly surprised to learn how Kacchan perceives him. Izuku replies that if he looked down on Katsuki, he would want nothing to do with him. But he stayed behind Kacchan because of all the amazing things he could do. Kacchan was always more talented than Izuku and was much closer to being a hero like All Might. Impassioned, Izuku subconsciously raises his limit on One For All from 5% to 8%. His speed increases and he uses a flying kick on Kacchan. Izuku states that it's because he believed Kacchan was so amazing that he always stayed close behind him.

Izuku lands his enhanced kick and breaks Kacchan's guard. He reels back from the hit and admits to himself that Deku has surpassed him. Katsuki blasts himself at Deku and he responds by charging back at extreme speeds. Katsuki narrowly ducks back under a flying kick. He tries to get the next hit in, but Izuku strikes him with a 8% charged smash. Izuku swiftly spins around and nearly cuts Kacchan down with an axe kick. In trouble, Katsuki detonates the ground to blast them both away. Katsuki realizes his opponent has kicked it into another gear as Izuku quickly charges right back at him. Izuku goads Kacchan by asking if that's all he's got. Izuku wouldn't say it to Kacchan's face, but Kacchan is the image Izuku sees when he visualizes victory. Deku got his habit of spouting insults in battle from him, even though it's something about Kacchan he hates.

Izuku leaps down at Kacchan from the air. Katsuki claims he has the upper hand in mid-air combat, but Izuku didn't jump for no reason. He knows Kacchan is ready for another kick. Izuku invented Shoot Style to stop abusing his arms, but he can still use punches at his set limit. Izuku punches Kacchan with a passionate, One For All-enhanced fist. Izuku isn't fighting with Kacchan just to relieve his stress, he wants to defeat him and live up to the expectations of being All Might's successor.

As Deku lays his fist deep into his rival's cheek, Katsuki recalls Deku proclaiming he would win using his borrowed power. Katsuki refuses to be defeated and grabs onto Izuku's punching arm. He pulls Deku down until he flips beneath him and then raises his hand before releasing a big explosion to crash them both into the ground. As the smoke settles, Katsuki pins Izuku down. Standing over his defeated rival, Katsuki claims victory. Despite having All Might's power, Izuku still loses to his childhood friend and Katsuki doesn't understand why.

Aftermath
All Might suddenly arrives and tells them both to break it up. Katsuki asks All Might why he chose Deku. All Might says that even though Izuku was powerless, he was still very heroic and selfless and believed that he had earned the right to inherit his powers and to compete with others. He tries to console Katsuki that he was always strong and already had a Quirk and didn't pay attention to him due to him already being talented and having the strength to compete with others. Emotional, Katsuki admits that he's weak and the reason All Might is now powerless. All Might tells Katsuki it's not his fault and he was going to lose his power eventually regardless. He embraces his student and apologizes for making him bear that burden.

Katsuki breaks out of the hug and All Might tells him that a hero needs the desire to win and to save people to uphold justice. Izuku always admired Kacchan's strength and Katsuki feared Deku's heart. Now that their feelings are out in the open, they both realize that they can make each other stronger so that they can win and save people. Somewhat relieved, Katsuki sits on the ground and tells Deku he shouldn't lose with All Might's power. Izuku replies that he will get stronger. Katsuki agrees not to release All Might's secret because he claims he doesn't want to deal with the repercussions of it getting out.

All Might tells Katsuki the whole truth about One For All and Katsuki agrees to keep the secret, as three of them leave Ground Beta. All Might reminds Katsuki that the end of the Symbol of Peace is not his fault. Katsuki replies that he still has the desire to surpass the old No. 1 hero anyway. He tells Deku he will focus on improving to surpass the chosen one. Izuku tells Kacchan that he'll surpass even that, and they start to go back and forth about it. All Might realizes that the two of them have taken a big step and finally become proper rivals.

Once the group gets back to Heights Alliance, Shota Aizawa restrains both his students for fighting past curfew. All Might tries to calm him and explains part of the situation. Shota lets them go but decides to punish them accordingly by asking who initiated it. Katsuki admits he hit first so he gets four days house arrest while Izuku gets three. During that time, they must clean the common areas every morning and night and submit a written apology. Shota tells them both not to go to Recovery Girl because they need to deal with the injuries they created.

The next day, both of them clean the main lodge while their classmates go to the second term opening ceremony. While vacuuming, Izuku asks Kacchan how his Shoot Style was to fight against. He doesn't expect an answer and is surprised when Katsuki talks to him normally. Katsuki tells Deku that his motions are too wide when he goes for kicks but he admits Deku's punch caught him off guard.