After witnessing the students’ impressive performance in the Battle Trial, the teachers arrange a trip to the Unforeseen Simulation Joint Facility to further train their rescue skills. However, the situation takes an unexpected turn when villains show up, forcing the students to engage in their first real-life battle against actual villains in order to survive.

During a training session to prepare for disasters, Class 1-A is accompanied by Aizawa and Thirteen to a specific area. Unexpectedly, they are ambushed by a large group of villains led by a young man named Tomura Shigaraki and his formidable ally, a black humanoid monster named Nomu. Shigaraki declares his intention to kill All Might.

Kurogiri, a villain with teleportation powers, scatters the students across different zones and fatally injures Thirteen when she tries to defend the students. Aizawa takes on the small villains by himself at the forefront. Eijiro and Katsuki are isolated on a destroyed building. Fumikage and Koji find themselves in a stormy city. Shoto is isolated and surrounded by villains. Momo, Kyoka, and Denki fight against villains in a stony area. Izuku, Tsuyu, and Mineta are together in a boat surrounded by water-based supervillains. The remaining class members at the entrance combine their strength to rescue Tenya and speed towards UA to get help.

Izuku combines the powers of Tsuyu and Mineta with his own to escape from the boat and trap the enemies underwater. Shoto and Katsuki effectively handle the enemies. Kyoka, Momo, and Denki, using practicality and cleverness, manage to apprehend the villains.

Izuku reaches the shore and is spotted by Shigaraki, who had just seriously injured Aizawa with the help of Nomu. Shigaraki threatens to use his power to harm Tsuyu, but All Might arrives just in time to save her. All Might battles the Nomu, which Shigaraki reveals was created specifically to fight All Might and can absorb impacts, making him immune to All Might’s power. Kurogiri and the Nomu team up to put All Might’s life in danger, but Eijiro, Katsuki, Shoto, and Izuku work together to keep him alive, while Tsuyu and Mineta help Aizawa to safety.

After figuring out a weakness in the Nomu’s powers, All Might defeats him but uses up his remaining time in his muscle form. He attempts to bluff Shigaraki and Kurogiri into retreating, but the teleporter convinces his boss that Nomu has weakened the pro enough for them to finish him off. As the two run up to try to kill All Might, Izuku suddenly bursts onto the scene and attempts to attack Shigaraki. Although he is no match for the two villains, his intervention distracts them just long enough for the other teachers to arrive, with Snipe shooting at Shigaraki with his gun. He and Kurogiri retreat and Izuku helps All Might cover his weakened form.

Shigaraki and Kurogiri are transported to a bar, where the young villain complains to a mysterious man through a computer monitor about the failure of their mission and admits that he was wrong about All Might being weaker. However, the person speaking to Shigaraki simply notes that they were overly optimistic in this case and assures him that next time, Shigaraki will show the world that he is someone to be feared.

In the school, the students are safe and sound, and their bravery against villains is praised. All Might introduces Midoriya to Naomasa, a police officer and his best friend, who is also aware of his secret. Naomasa confirms that Aizawa and Thirteen will fully recover in time and acknowledges that All Might’s intervention likely saved the children’s lives. However, All Might denies this, attributing the successful outcome to the students’ abilities and stating that they will all become excellent heroes.

Tropes

• Adaptation Expansion: In the anime, All Might’s fight with Nomu lasts a few minutes. All Might throws Nomu up and down, destroying the ground and the ceiling with his punches. Additionally, we catch glimpses of other students, like Mashirao, fighting villains.
• All Women Are Prudes: When Momo’s costume is torn up by her Creation Quirk, Kyoka, having little tolerance for nudity, is more embarrassed by Momo’s skin exposure than she is.
• The main villain is Tomura Shigaraki, with Nomu serving as the heavy.
• Big Damn Heroes:
  • After Izuku is dropped into the water zone and almost gets eaten by a shark-based villain, Tsuyu appears out of nowhere, drop-kicks the shark’s face, and wraps her tongue around Izuku before swimming away.
  • When All Might suddenly arrives at the USJ, he busts down the door and reassures his students. He then proceeds to take down several minor villains, although he finds out that Nomu is a far more difficult opponent.
  • Katsuki, Eijiro, and Shoto arrive on the scene to save All Might from being bisected, allowing the Symbol of Peace to rise and resume fighting.
  • Izuku flies towards All Might, attempting to stop Shigaraki from touching him. Although he is unable to do much against the villain and almost gets killed, his intervention distracts the villains long enough for the teachers to arrive. All Might later thanks Izuku and tells him that he would have died if it weren’t for him.
  • The other teachers arrive and quickly defeat the low-ranked villains, rescuing Denki from the electric-based villain and severely injuring Shigaraki. Kurogiri then decides to escape with his boss.
• Bittersweet Ending: The situation is more on the sweet side than bitter. The students were rescued from unforeseen danger with little to no injuries during their first encounter with a villain. However, the majority of the League members were captured. Despite sustaining major injuries, Aizawa and Thirteen survived. All Might has further shortened his usage of One For All, and it has been revealed that things are only going to get worse from here, with a hint that Shigaraki will become a much greater threat in the future.
• Bloodier and Gorier: Aizawa’s injuries and Snipe shooting Shigaraki’s limbs are much bloodier in the anime than they were in the manga.
• Cerebus Syndrome: Things take a dark turn when the League of Villains shows up, as most of the students have never encountered actual villains up close.
• Characterization Marches On: Shigaraki behaves very differently in his first appearance compared to subsequent ones. He is more unhinged, nervous, and prone to using video game lingo as metaphors. In his next appearance, he uses video game lingo to a much lesser degree and is not nearly as nervous. This change is slightly justified since it is his first solo mission for the League of Villains.
• Chronic Hero Syndrome:All Might’s habit of involving himself in every minor confrontation he comes across is deconstructed in this storyline. Spending the entire morning dealing with small-time villains that other heroes could handle, he ends up using up all his time and is unable to make it to the USJ. As a result, when he finally arrives, he only has a limited amount of time to defeat Nomu before he becomes exhausted. After the battle, he can barely stand and defend himself when Shigaraki and Kurogiri attack him.
• Conservation of Ninjutsu: Invoked by the League of Villains during their raid on the USJ. The majority of villains are rough and tumble thugs, but they’ve been saving Nomu specifically for All Might.
• Curb-Stomp Battle:Shoto easily takes out the thugs that the League of Villains brings to attack USJ.
• Darker and Edgier: Comparing to previous story arcs, we finally have a real confrontation with dangerous villains.
• Exact Words:Important during All Might’s battle with Nomu.
• All Might: He said your quirk is shock absorption, not nullification! That means there’s a limit to what you can endure, right?!
• Failed a Spot Check: The villains never bothered to look up the students’ Quirks before storming the USJ. Many of them were defeated by the students and teleported to different areas. Only a few were lucky enough to capture them before All Might and the other Pros arrived to stop them. Izuku realizes that while he, Tsuyu, and Mineta have been sent to a water area, Tsuyu’s Frog Quirk gives them a good advantage thanks to her jumping ability.
• Kung-Fu Sonic Boom:The clash between All Might and Nomu created gale-force winds, preventing anyone from approaching the fight within several meters.
• Near-Villain Victory: The plan was somewhat haphazard, but the League came alarmingly close to succeeding in their attempt to kill All Might multiple times. If not for the students’ multiple interventions, it’s very possible that the Symbol of Peace would have been killed then and there.
• Nose Bleed: Denki notices Momo’s costume has been torn up by her Creation Quirk and gets her a new one.
• O.O.C. Is Serious Business: Izuku always sees All Might performing heroics with an iconic smile on his face, so he knows things are about to get serious when the Pro Hero is seen without one.
• Pervert Revenge Mode: When Mineta touches Tsuyu’s breasts twice during the arc, she slams him onto the boat, and later dunks him to the point of near-drowning.
• Red Herring: Nomu was not meant to kill All Might; he was meant to simply contain him. Kurogiri was supposed to kill him by bisecting him with his portal quirk. Fortunately, this did not happen.
• Red Herring: Nomu wasn’t meant to kill All Might; he was meant to simply contain him. Kurogiri was supposed to kill him by bisecting him with his portal quirk. Thankfully, this doesn’t happen.
• The Stinger: In the 13th and final episode of the 1st season, there is a post-credit scene where we get our first look at Hero Killer Stain, hanging on the rooftop of a building, serving as the Knight of Cerebus.
• Things Get Real: The students find themselves battling real villains during a routine training session.
• We Will Meet Again: While being teleported away, Shigaraki tells All Might that he hasn’t seen the last of the League and promises that one day he will succeed in killing him.
• Wham Episode: Chapter 13 begins as a typical daily lesson chapter, but escalates into a life-and-death situation when the League of Villains reveal themselves to the students.