At the beginning of summer vacation at her first year of middle school, Manami wrote a long love letter to a schoolmate she liked who, in return, dismissed said letter and made fun of her with his friends, thinking of her as a stalker. Pained by the rejection and the mockery, Manami stopped believing in anything and fell into a depressive state.
She became a reclusive adolescent with no goals or aspirations, gluing herself to her computer all day long, even contemplating suicide. One day while surfing the net, Manami came across one of Gentle Criminal's videos about him changing the world's deplorable state for the better that she managed to pull herself together.
Now considering Gentle as her light, and desired to meet him. Manami used her computer skills to find the place where he lived. She introduced herself to him as his greatest fan, eager to help him to achieve his dreams. She wanted to go out with him on their capers instead of staying back to do the hacking. At first, Gentle didn’t want her to become an accomplice to his misdeeds, but he eventually caved to her demands.
After spending time with him, Manami became attracted to him. Her only concern was Gentle would say something about the dark rings under her eyes, but he didn't. In fact, when he realized her concerns, he uses 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 when he decided to make her his sidekick, he came upon her code name, La Brava. That was one of the happiest moments of her life. 
La Brava is recording Gentle Criminal as he robs a convenience store. When a group of heroes arrive to stop them, La Brava cuts the video at the request of Gentle, only to restart it once the heroes have been defeated. Later, on a rooftop, she informs Gentle that their video of the robbery isn't receiving as many views as they had hoped. While busily monologuing, Gentle accidentally spills tea on La Brava.
The next day, because their account had been deleted again, La Brava uploads all Gentle's videos and takes pleasure watching Gentle's debut video. La Brava gushes over Gentle as Gentle himself asks her if the convenience Store robbery video has been uploaded. She replies that she already uploaded it. Gentle appreciates La Brava's hard work as he pours himself a cup of tea. Gentle tells La Brava that they will commence with today's video after he has drunk his tea.
The video, Gentle Criminal labels himself as a modern-day gentleman thief who punishes those who behave in an ungentlemanly way, such as attacking the Store for hiding expiration dates of Plump Pudding that was about to expire, even though there was evidence about the misgivings of the sales. After uploading the Store video, La Brava is infuriated that the video has not gotten any views despite Gentle's dashing performance.
La Brava tells Gentle 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, and points out the differences between them. La Brava and Gentle talk about their next project which involves U.A.'s School Festival. Gentle believes that if he invades U.A’s School Festival, he could become the center of attention.
During the following days until the festival is celebrated, Gentle is seen working non-stop on his next project, this is worrying La Brava since he has not had a tea break in an entire week. As La Brava goes to fetch some tea, Gentle comments that there is a growing discontent towards heroes among people and praises U.A.'s preparations but criticizes their resourcefulness when faced with the unpredictable. La Brava is concerned with the idea of sneak into the U.A. School Festival and asks what about the students. Gentle reassures her by telling her that with the infiltration is a wake-up call for them to grow stronger. La Brava gets goosebumps by Gentle's response.
On his computer, Gentle decides to double check the route they will take to get to U.A.'s School Festival, a plan that consists of first spending a good time in a café enjoying a cup of Gold Tips Imperial Black Tea before infiltrating the U.A. La Brava has a fundamental role in this operation because she 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, glad to have a partner like her and remembers when she went to his home, proclaiming to be his fan and eager to help him to carve his name into history. Thanks to her help and computer skills his popularity increased. Gentle ensures La Brava that he will make the U.A. infiltration a success to not secure the future of the world but as a response to her feelings. Crying tears of joy, La Brava hugs Gentle, proclaiming her love for him, to which Gentle replies he loves her too, and vows to succeed in the infiltration.
On the day of the attack, a disguised Gentle and La Brava run into Izuku, who apologizes, while the disguised Gentle is more worried about losing the aftertaste of the Golden Tips Imperial. Gentle and La Brava attempt to leave wanting to avoid further contact but after hearing that Izuku has some knowledge about tea, Gentle cannot help praising him, although he and La Brava both know that they are endangering the mission.
Their worst fears are fulfilled when Danjuro is aware that Izuku is a student of the U.A., and Izuku manages to figure out his identity as the villainous Gentle Criminal, and deduces that he and La Brava intend to cause problems at the festival. Seeing that it is too late to cover up since Izuku is not naive, Gentle faces Izuku as he tells La Brava to turn the camera towards him.
While La Brava recognizes Izuku from somewhere Gentle tells her there's been a change of plans and to keep the camera recording no matter what. He removes his cape and hat and tells his listeners to bear witness to his dazzling ambitions. When Gentle blasts Izuku across the street using his Quirk, La Brava becomes surprised at his elasticity power. They both decide to escape, but Izuku gets up and chases them, so Gentle sends him through the air with his Gently Trampoline. Gentle bids Izuku farewell as they bounce away on his Gently Trampolines.
La Brava remembers that Izuku is from U.A's Sports Festival and tells Gentle this fact, which surprises Gentle who doesn't want to be involved with Izuku further and decides to quickly infiltrate U.A before the boy gets the chance to alert them. Deku manages to stabilize in the middle of the air, and shoots Gentle a Delaware Smash Air Force, then swoops over him, smashing him into a construction building as La Brava cries out.
A civilian who was walking around witnesses this, but La Brava excuses Izuku and Gentle's battle with the statement that they are filming and asks him to transmit it to the neighbors, although La Brava is aware that this lie will not make them buy much time. Desperate to the idea that her beloved Gentle may be having problems, La Brava runs towards the construction site and reaches them, just to be shocked to see Gentle hanging on a construction beam and pleading Izuku to let him go.
Izuku tells Gentle that the moment he enters U.A.'s School Festival, the alarm will go off and the festival will be cancelled immediately with nowhere for him to run. Gentle mentions alarms do not concern him as his partner in crime, La Brava, will render the alarms ineffective. In this way his plan can succeed and the festival will not be suspended, a win-win situation for both. Izuku quickly refutes his argument saying that it will make an even bigger problem, and Gentle can’t deny that Izuku is right, which shocks La Brava again.
Knowing that Izuku has no intention of letting him go, Gentle resumes the fight. La Brava asks him to retreat. He tells her not yet and uses his Elasticity Quirk to remove the bolts from the steel structure, warning Izuku that one of the steel beams can fall on the bystander with which La Brava met before. As Elasticity’s effects wear off, the structure collapses and Izuku swiftly catches the steel beam and barely holds it up.Determined not to continue the fight, Gentle uses his Quirk to turn a crane's hook into a slingshot and launches himself and La Brava out of the construction site. Izuku attempts to stop them by firing a long range attack but Gentle dodges it. La Brava sees that Izuku refuses to give up and that she has no choice but to use her Quirk.
Retreating from the construction site Gentle and La Brava discuss her Quirk until they are interrupted by Izuku appearing above them. Charging at them at them with super speed, Izuku manages to pin them both down on the ground. Looking at Gentle she shares her love for him which empowers him to overthrow Izuku. As Gentle delivers an attack on Izuku, La Brava watches on, only for Izuku to be unaffected.
When they are knocked back by Izuku's attack, La Brava becomes emotional and apologizes for her love not being enough. Gentle tells her that nothing can prove that her feelings weren't enough. Watching on as Gentle and Izuku continue to fight, she cries out for him to win.
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. 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 moves 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.
La Brava returns to Gentle and sees that he has been defeated by Izuku. Gentle orders her to run away, but a crying and flabbergasted La Brava demands Izuku to let Gentle go and while hitting Izuku, yells 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. As Hound Dog and the Ectoplasm clones reach Gentle and La Brava, they declare their surrender.
Wanting to protect La Brava and having a heart for looking out for others, Gentle lies about kidnapping La Brava and brainwashing her, requesting to pardon La Brava as Izuku arrives back, who understands what Gentle tries to do and plays along. The teachers takes Gentle and La Brava to the police station.
Later, at the Police Station, the investigators are astounded by Manami Aiba's hacking talent and wonder if she has ever used her advanced computer skills for the sake of the world, to which she states that everything she does is for Gentle's sake.