When he was a teenager, Danjuro Tobita wanted to be a hero whose name will be in the textbooks. However, his grades were terrible, was repeating years at his high school which was not highly regarded and failed the Provisional Hero License Exam four times. One day, he was called into the office of his school and the life councilor urged Danjuro to drop out in his endeavor as he was not cut out to be a Hero, no matter how hard he tried.
This brought his mother to tears, but Danjuro was not discouraged and told his mom he would keep doing his best. As they prepared to back to their home, Danjuro saw his classmate Takeshita, who already has his license and many Hero agencies are asking for him.One day, after enjoying a cup of tea in a coffeehouse, Danjuro saw a man falling from a window cleaning rig. Danjuro attempted to be a Hero and tried to save a falling man by creating a elastic surface to jump to the rescue. However, the elastic surface prevented a pro hero from saving the falling man. As a result, the victim hit the ground and needs six months to recover.
The police gave Gentle a strike for obstructing justice and his parents ended up deep in debt paying reparations to the victim and fines for hindering a hero and unlicensed use of a Quirk. During this time, he was finally expelled from school, which caused his parents to no longer support him and throw him out of the house. All this made him give up on his dream of becoming a hero. Eventually, Danjuro found accommodations to rent and lived as a freeter for fours years.At age 22, Danjuro was walking down the streets merrily and spotted his old classmate Takeshita, who had become a successful Pro Hero. Danjuro ran into him to congratulate him and told him that they were in the same class together, but he found that his classmate didn't even remember his name. Devastated, Danjuro realized that he was going to live a miserable life to the point of being old and pitiful. Refusing to accept this fate is what resorted him into becoming a villain.
Six years ago, Danjuro became a villain of the online world, under the name of Gentle Criminal, uploading videos about his actions though he has been mostly unsuccessful at gaining popularity during his criminal career. However, his videos inspired Manami Aiba, a young woman who was going through a deep depression. Desiring to meet him, she used her computer skills to locate Gentle, presenting herself as his greatest fan and eager to help him achieve his dreamsAlthough at first he liked the idea of having a fan, Danjuro did not want Manami to participate in his villain actions, since that would make her also be persecuted by the police as a villain. Still, after spending some time together, during which Manami always helped him with her computer skills. Danjuro began to appreciate her. When he realized her concerns about her dark eyeliners, he used a permanent marker to gives himself dark circles around his eyes so they could match her's. He accepted her for who she was, and decided to make her his sidekick and gave her the villain name La Brava. 
Danjuro is robbing a store, with La Brava recording the whole robbery. Some Heroes try to stop him, but he easily defeats them after ordering La Brava to stop filming. Then they continue recording, with the heroes defeated on the ground and the store wiggling like a jelly. Danjuro is walking away without even taking his cash, revealing himself to the world to be Gentle, a fancy and lavish-style villain whose true goal is that his name goes down in history.
On top of a building, La Brava informs Gentle that their latest video isn't getting a lot of views. Gentle sees that he will have to accomplish a lot more if he wants people to start taking notice of him. While pouring tea, Gentle tells La Brava that he is searching for something that will make him extraordinary.
Later at their home, Gentle asks La Brava if the video of the robbery has been uploaded. She says yes. In that video, Gentle explains to the viewers that he commits crimes for reasons such as attacking the J Store for hiding expiration dates of Fluffy Pudding that was about to expire even though there was evidence about the misgivings of the sales. Despite this, the pudding company selling the pudding feigned ignorance and tried to sidestep the matter. Gentle explains that he hands out punishments to those who do not act "gentlemanly", labeling himself as a modern-day gentleman thief.
After uploading the Store video, La Brava becomes infuriated that the video has not got any views. Gentle tries to downplay it, but La Brava is enraged because, despite the fact that he has been a villain in online videos for six years. She thinks that Stain's biographical video stole the spotlight from them, as well as the prominence of the League of Villains. Gentle agrees with La Brava on the fact that violence can make a spectacle, pointing out the differences in style between them and him.
However, Gentle is not disparaged about the popularity of Stain and the League of Villains because the next project will surpass even theirs, which involves U.A. High School's Culture Festival. As the school was fortified after being attacked and is the current symbol of the Heroes, Gentle believes that if he invades the festival, then he will become the center of attention.
During the following weeks, until the festival is celebrated, Gentle is seen working non-stop. As La Brava goes to fetch some tea, Gentle notes that dissatisfaction is growing towards Heroes nowadays because of their feeble-minded nature. Gentle praises U.A.'s preparations but criticizes their resourcefulness when faced with the unpredictable. La Brava wonders if Gentle will involve the U.A. students, he replies that simply invading U.A.'s School Festival in and of itself is a wake-up call for them to grow stronger, which La Brava finds cool.
On his computer, Gentle decides to double-check the route they will take to get to U.A.'s School Festival. Gentle goes through a long spiel about the way to get to a lonesome house that is actually a café where he can enjoy 90-minutes of teatime, drinking "Imperial Golden Tips" tea. He vows that they will infiltrate the U.A. To achieve this they must rub with dirt and leaves to mark their scent and thus avoid being detected by Hound Dog, who will be responsible for patrolling the perimeter. And to surpass the U.A,'s Barrier, La Brava will use her hacking skills to infiltrate the U.A.'s internal network and disable the sensors.
Gentle praises La Brava for her excellent support, and thanks her for all her help she provided him from the day she arrived at his home. Gentle ensures that he will make the U.A. infiltration a success not only to secure the future of the world but as a response to her love. Crying tears of joy, La Brava hugs Gentle and proclaims her love for him, to which Gentle reiterates the same line of thought and vows to succeed in their U.A. School Festival infiltration.
On the day of the attack, a disguised Gentle and La Brava run into Izuku Midoriya. Izuku apologizes while the disguised Gentle is more worried about losing the aftertaste of the Golden Tips Imperial tea he had just drunk. Gentle and La Brava attempt to leave wanting to avoid further contact. Hearing them talking about coffee, Izuku notes that the house was a coffee shop which grabs Gentle's attention. Gentle is impressed that Izuku knows of the Golden Tips Imperial tea, and Izuku admits that a friend served some to their class.
Izuku finds the disguised man's voice familiar while Gentle praises Izuku's friend but soon deduces that Izuku is from U.A. Suddenly, Izuku manages to figure out his identity. Gentle sees that it is too late to cover up since Izuku is not naive, he turns around and takes his mask off asking who Izuku was referring to. Izuku tells Gentle that he saw his video; Gentle faces Izuku as he tells La Brava to turn the camera towards him. Izuku prepares himself and tells Gentle to leave U.A. alone.
Gentle praises Izuku for figuring out his identity while Izuku charges at Gentle but suddenly stops moving as he has run into an elastic sheet. Gentle reveals his Quirk's abilities. Gentle uses Gently Rebound on Izuku which blasts him across the street, as he comments on his dislike for using violence to solve his problems. Gentle and La Brava attempt to make their escape but Izuku comes charging at them.
Gentle turns around and uses his Quirk on the ground. Izuku gets caught by Gentle's Gently Trampoline and is shot into the air. La Brava remembers that Izuku is from U.A's Sports Festival and tells Gentle this fact, which surprises Gentle who now wishes to not be further involved with Izuku and decides to quickly infiltrate U.A.
As Deku recovers from Gentle's attack in midair, he recalls everything that's riding on the School Festival. He is aware that Gentle's infiltration into the festival would cause its cancellation, so he is not willing that something for which the students have worked so hard is ruined.
Deku clears his head of all doubts and shoots a Delaware Smash Air Force, hitting Gentle right in the back mid-air. It only stops Danjuro for a moment, but its enough for Izuku to lunge off a utility pole and grab onto the criminal. Izuku fiercely declares that his feelings are shared by everyone involved with the festival and they will not waver for Gentle's plan, culminating into a full-on brawl between Gentle and Midoriya as the two crash into a construction building.
Gentle's jacket is caught on a construction beam, hanging him in mid-air. Danjuro tries to convince Izuku to allow him to infiltrate the Festival, as it is the only thing he wants to do and there will be no problem in it, assuring him that the alarms will not sound, but Izuku refutes his arguments, determined to prevent Gentle from continuing with his plan.
Aware that he will not be able to convince him, Gentle jumps into the air using an elastic trampoline, but Izuku charges at him until he starts bouncing around Izuku at great speed by turning the construction beams around him into elastic. Izuku fires another air pressure shoot, but Gentle's Quirk causes the projectile to bounce and eventually impact Deku himself.
Gentle stops on a beam and tells his young adversary that he removed the bolts from the steel structure and its bound to collapse. Elasticity can't be remotely deactivated and anything it effects with gradually returns to normal. Izuku makes note of an old bystander who just happens to stand by the construction site because of the commotion that was causing their fight. As the Elasticity effects wear off, the structure collapses and Izuku swiftly catches the steel beam and barely holds it up, saving the bystander.
Izuku is angered because Gentle tried to harm a civilian, but Gentle explains that he was going to bounce the beam away from the civilian if Izuku didn't move, but he counted on the U.A. student leaping into action. As the civilian runs away, Gentle makes a crane arm elastic, planning to use it as a slingshot to launch himself and La Brava towards the U.A., and tells Izuku to stay put while he finishes his plan before sending himself flying away. Using his enhanced strength, Izuku fires a long-range attack at Gentle and La Brava. Gentle dodges it and notes Izuku's tenacity.
Holding La Brava, Gentle uses his Elasticity Quirk to create invisible trampolines to control his fall and land safely in the forest area. Gentle and La Brava discuss her quirk until they are interrupted by Izuku appearing above them, ready to shoot another air blast, so he raises an elastic invisible barrier in front of him and La Brava. Using the same aerial trampolines Gentle created to gets behind him and Deku aims precisely to shoot at his barriers to ricochet his attack right at Gentle.
La Brava goes to help Gentle, but Izuku manages to pin them both down on the ground, ordering them to surrender. Looking at La Brava, she uses her Quirk Love. Gentle thanks her as she speaks of her love for him, which activates the Lover Mode that grants him power up to overthrow Izuku. Wanting to end the battle quickly while apologizing to Izuku, the powered-up Gentle delivers an enhanced karate chop to the back of Izuku's neck. However, Izuku manages to block his attack with his arm and prepares to fire a Delaware Smash Air Force at the powered up Gentle.
When they are knocked back by Izuku's attack, Gentle refers to him as incorrigible. La Brava apologizes for her love not being enough but Gentle tells her nothing can prove that her feelings weren't enough. He attacks Izuku with a Gently Sandwich claiming he must fulfill his fleeting dream. Revealing the more he tells him to give up the more determined he becomes. When he's asked why he must infiltrate the festival he says there's no other way for him to further his goals. As Izuku gets up he tries to throw him but is quickly rebounded by the latter. They then proceed to clash with each other.
Izuku and Gentle clash with La Brava cheering Gentle on. Izuku is beginning to be overpowered by Gentle's enhanced strength which Izuku assumes to be the work of La Brava's Quirk. Gentle asks Izuku why he aspires to become a Hero. Izuku answers that just like Gentle his dream is no longer his and will achieve his dream for the sake of those who believed in him, wanting to be the man who shows everyone a brighter future. Izuku's response brings a smile to Gentle's face.
As Gentle knocks back Izuku, La Brava takes the opportunity and brings out her computer and using special wireless technology plans to hack into U.A's internal network to disarm its security. However, she is out of range and tries to move closer.
Izuku sees this but Gentle plans on keeping Izuku occupied longer; Gentle jumps from his aerial elastic barrier and lunges into Izuku who manages to keep his guard up, mitigating the damage. Gentle creates several aerial elastic barriers and jumps from them all over the vicinity hitting Izuku and knocking him down. Gentle yells that he will discard his reputation and style of fighting to defeat Izuku, having developed a respect for the boy.
Meanwhile, La Brava has moved closer to U.A but isn't able to proceed further as Hound Dog and several clones of Ectoplasm have caught a whiff of Izuku and Gentle's battle. On the ground, Izuku launches several wind pressure attacks that Gentle manages to evade most of but is hit by one of them. Gentle loses his balance and is stunned as a result of Izuku's air pressure attack. Using this opportunity, Izuku jumps in front of Gentle and attacks him with Shoot Style: St. Louis Smash. The strength of Izuku's St. Louis Smash is enough to finally bring down Gentle and render him immobile. Izuku apprehends Gentle and admits that out of all the battles he has fought, the one with him has been the toughest so far.
La Brava returns to Gentle and sees that he has been defeated by Izuku as Gentle orders her to run away. Devastated, a crying and flabbergasted La Brava demands Izuku to let Gentle go and while hitting Izuku, lamenting that Gentle poured his heart and soul into their U.A infiltration plan and that she is unable to live without him. Knowing that La Brava is fine with committing criminal acts as long as it's with him, Gentle realizes that if he allows La Brava to escape she will go on to committing an even worse crime.
Blaming himself for La Brava's nature and knowing that she will be charged as being an accomplice, Gentle musters up the remaining strength given to him by La Brava's Quirk and pushes Izuku off and into the air, using his Quirk to bounce Izuku away. Gentle hugs La Brava as he tells Izuku to fly away for the sake of La Brava's bright future. Hound Dog and the Ectoplasm clones find Gentle and La Brava, as Gentle declares his surrender.
One of the Ectoplasm clones recognizes Gentle as a villain who is always quick to run away. Hound Dog grabs Gentle and demands the whereabouts of Gentle's comrades, to which Gentle denies having any more comrades. Seeing him dirty and scratched Hound asks Gentle what happened, he replies that he just tripped and fell, but Dog doesn't buy it as he smells one of U.A.'s students.
As he is interrogated by Hound Dog, Gentle downplays La Brava’s role in his crimes and insists that he brainwashed her. When asked about his injuries, he claims he got them in a fall, and when confronted about Izuku’s scent on him, points Hound Dog in his direction. Gentle is glad that his last fight was with Izuku as La Brava cries inconsolably. Hound Dog questions to Izuku if they had a fight. Understanding that Gentle is trying to protect La Brava, Izuku replies that Gentle was trying to pull a prank on U.A and they got into a small dispute but that everything is fine now. 
Hound Dog, though suspicious, reports back that there is no threat to U.A. and the Cultural Festival can continue without issue. Then, the teachers take Gentle and La Brava to the police station. While being escorted, Gentle tells Izuku that he used to be enrolled in the Hero Course and became a villain when he was dropped out of the course. After remembering the words Izuku said to him during their fight, he hopes that Izuku's feelings can reach others.
Sometime late, during a police interview, a gorilla-looking investigator interrogates Tobita who states that he believes that Manami is brainwashed and will run tests on her. The investigator lumps Manami with Tobita's crimes, but Tobita adamantly believes that Manami has nothing to do with his crimes, to which the investigator starts believing that there is a mutual love between the two instead of brainwashing.
The investigator goes over Tobita's past; Tobita states that he started remembering his dream and started running towards it even if it was on the incorrect path. The investigator is glad that they were able to stop Tobita before hitting rock bottom and that he has the motivation to rebuild his life unlike those who are lazy or those who rush to get results.
Before continuing, the investigator decides to get some tea, to which Tobita requests black tea but the investigator denies Tobita's request and goes to get instant tea.