Determined to participate in Hero Work-Studies, Izuku calls Gran Torino to see if he'll take him in. Gran Torino acts senile like he doesn't remember Izuku at first, and then calls him the useless successor. Izuku replies that he wants to be a useless successor who needs to live up to All Might. Gran Torino can't take him on because he's busy working with the police. He tells the young Izuku to ask All Might to introduce him to his old sidekick, Sir Nighteye.
Meanwhile, Twice leads Overhaul to an abandoned factory to meet with the others. Overhaul claims he'll get sick from all the dust, but Twice reassures him everyone inside is sick. Tomura recognizes Overhaul as the young boss of the Shie Hassaikai, one of the yakuza that All For One showed him before. Himiko Toga asks how someone involved in organized crime is different from the League of Villains.
Compress explains that the yakuza used to run the underworld before the age of heroes. Following the rise of All Might, the yakuza became nearly extinct and live under constant surveillance. Ashamed, even Overhaul is inclined to agree on the sorry state of the yakuza. Magne asks what Overhaul wants and asks if he's riding the high of All Might's retirement. However, Overhaul reveals quite the opposite, he wishes to become the emperor of darkness now that All For One has fallen.
Their society is without a leader of light or darkness and asks who will lead now. Tomura claims that he will lead and is insulted by Overhaul's question because the yakuza knows full well who Tomura's master is. He claims the League of Villains with crush hero society, but Overhaul asks if they have a plan. Overhaul argues a goal with no plan is a delusion and says Tomura wasted first-class soldiers like Stain, Muscular, and Moonfish.
Overhaul reveals that he has a plan and he's come here today to ask the League of Villains to join him, not vise versa. He needs money for his plan and needs the League of Villain's name to convince dark investors. Overhaul believes he'll be the next leader and Tomura demands he leave immediately.
Irate, Magne refuses to serve under anyone and activates her Quirk on Overhaul. She reveals that she talked to a friend that inspired Big Sis to live on without ties or without being bonded to anything. Magne strikes Overhaul with her magnet pole, but he suddenly takes off his glove and swipes her arm with his finger. In a flash, Magne's upper body expands and explodes into a pool of blood, killing her in seconds.
Compress tries to take out Overhaul with his Quirk, but he's struck with a mysterious bullet and his Quirk won't activate. Overhaul destroys Compress's arm and Tomura rushes him head-on. The next bullet misses Tomura and Overhaul calls a shield to protect him. One of Overhaul's followers suddenly appears and sacrifices himself to protect the young boss.
More of the Shie Hassaikai bust through the warehouse wall to back him up. Twice was sure no one followed him but Tomura says it's probably someone's Quirk. Overhaul claims both sides have lost one man and they should call it even. He asks them to cool their heads to they can resume discussions another day. Twice and Toga want to murder the masked assailant, but Tomura wards them off.
Overhaul leaves and asks Tomura to call him soon after leaving his card. Twice checks on Compress's condition and Himiko is furious over Magne's death. Tomura recalls All For One's advice and even considers Overhaul's words to formulate a plan. Next time they meet, Tomura will demand a lot of repayment.
Back at Class 1-A, Shota Aizawa explains the Hero Work-Studies to his class. He adds that most teachers believe they shouldn't participate but will ultimately allow them to go to agencies with good reputations. After class, Izuku asks All Might to introduce him to Sir Nighteye. All Might refuses because he doesn't think Izuku necessarily needs to participate and he's not exactly on good terms with Sir Nighteye.
Izuku asks All Might to reconsider but he still won't introduce him. Instead, All Might calls Mirio to his office. They announce it over the loudspeaker, and the Big 3 are surprised to hear. Mirio arrives and asks why All Might needs him to do it and All Might replies that he can't face Sir Nighteye right now.
Mirio asks Izuku what kind of hero he wants to be and he says he wants to be the greatest hero who can win and save everyone. Mirio agrees to help Izuku and says he thinks Sir Nighteye would like him. While the two boys speak, All Might recalls Nezu telling him that Mirio would be his successor.
That weekend, Katsuki and Shoto leave for Provisional Hero License training. Izuku rushes out of the dorms in a hurry and Mirio takes him to the Nighteye Agency an hour away from school. Mirio warns Izuku that Sir is very strict and he must do his best to try and make him laugh before the end of the day. Sir Nighteye holds humor in high regard and Izuku must impress him on his own without too much of Mirio's help.
Bubble Girl reports to Sir Nighteye about the League of Villains recent skirmish. Sir interrupts her and claims there is no room for a society without humor. Izuku enters Nighteye's agency and is shocked to see Nighteye torturing Bubble Girl with his tickle machine for not making him laugh.
Sir Nighteye glares at Izuku and he tries to calm the mood by making his face take on an expression akin to that of All Might's. Mirio is shocked by Izuku's one and only plan. Unimpressed, Sir Nighteye doesn't laugh and asks if Izuku is making fun of All Might.
Anime and Manga Differences
- Overhaul’s Quirk has more visual flair to it. It manifests as bumps under his skin and when used, it causes the target's skin to bubble up until it explodes.
- The aftermath of the conflict between Overhaul and the League of Villains is extended to show the Shie Hassaikai leaving, and Himiko telling Twice they need to get Compress to a doctor. Compress expresses his pain and Himiko looks at her knife, asking to kill Overhaul. Tomura’s revenge is foreshadowed when he thinks to himself that he will demand repayment for what happened.
- All For One makes a cameo in his cell (it’s the same cameo he made at the end of Season 3).
- When All Might wants to talk to Mirio, it shows him being called as he is walking with Nejire and Tamaki. They wonder why All Might wants to talk to him and Mirio says he has “To-gata-go” see.