Chapter 1 (Team-Up Missions)

Team-Up Missions Begin (まれ) is the first chapter for My Hero Academia: Team-Up Missions, written and illustrated by Yoco Akiyama.

Summary
Izuku, Ochaco, and Katsuki arrive at a Hero Office to begin their first Team-Up Mission. Annoyed because Deku is taking the lead, Katsuki blasts him.

Several days ago, All Might announced due to them all having their Provisional Hero License they can now participate in a new program. All Might told Class 1-A about Team-Up Missions and how it's suppose to increase teamwork and communication within the Heroes. Everyone was handed a Mission envelope where Izuku found his first team-up with Ochaco, to his joy, and with Katsuki, to his misfortune.

Back to the present, the three students wait at the reception of the building, which is a Hotel and not an Hero Agency as they thought at first. Suddenly, a voice calls for them. When they all turn around to find out who it is, Izuku quickly recognizes her as the Rabbit Hero: Mirko. Izuku tells Ochaco and Katsuki that Mirko is a unique Hero because she doesn't stick to one location and has no proper Hero Office nor sidekicks, which she responds with a "Thank You". Izuku is excited to start his Mission when Mirko tells them she doesn't really care because she prefers working alone and only agreed because she got orders from the Hero Public Safety Commission. Mirko tells them they're free to follow her and they agree to the circumstance.

Soon after, a villain is causing havoc when Mirko comes in with a kick, knocking them out. As Izuku and Ochaco praise Mirko, a little boy's Gang Orca balloon floats away. Ochaco uses Zero Gravity on herself and returns it back to him. The boy thanks Ochaco followed by her calling him an angel. Izuku is happy for Ochaco and wants to do his best when Katuski begins shouting.

Katsuki is asking where are the villains are, which causes the locals to flee. Izuku tells Katsuki he is scaring people, but when Katsuki asks him if he has a problem, Izuku quickly responds with a no. A hooded figure passes by them noticing his costume asking if he is a hero. Izuku explains he is still a student but doing hero work due to school. The hooded figure comments that it must be nice being able to use his Quirk freely. Izuku asks the hooded figure why they're so pale but the hooded figure says not to approach them any further and walks away. Izuku wonders if the hooded figure was sick.

Later, Mirko tells her "Team" she didn't plan to teach them anything but tells Katsuki his attitude to kill Villains is great. Ochaco is praised for helping the boy, while Izuku is scolded for doing anything.

Elsewhere, the hooded figure begins to feel unwell and needs to use his Quirk and begins leaking out a poisonous gas. The gas causes a nearby man to fall, while it continues to spread. Civilians start rushing into the Hotel where Mirko's "Team" is currently at and is told what's occurring. The news comes on reconfirming the situation and that the poisonous gas is spreading across the Sarumai District and to seek shelter. The news confirms the source is Takeshi Bushijima using his Poison Gas Quirk. Izuku comments on how dangerous it is and asks what Mirko will do. Mirko tells them she is going go kick Takeshi's butt and heads out.

Mirko and her "Team" now equipped with gas mask begin to evacuate the area, with Izuku using the One For All to prevent the venomous fog from spreading. With the gas dissolving, Ochaco floats high up to scope where the gas source is currently coming from. Ochacho finds Takeshi on the edge of town, where he is trying to stay away from everyone. Katsuki and Izuku immediately go towards his direction. Takeshi is about to leave the alleys, but seeing that there were too many people at the streets, he decides to take another passageway, leaving Izuku confused on his intentions. They almost catch up to him, while Takeshi continues avoiding the civilians.

Mirko's "Team" finally surrounds him but Izuku believes something must be up. Before Katsuki can land a hit on Takeshi, Izuku stops him. Katsuki questions Izuku due to Takeshi being a villain, but Izuku explains that he has been purposely avoiding everyone due to not being able to handle his Quirk. Takeshi tells them it's true and his Quirk accumulates over time and he can't use it freely due to the laws which forces him to store it. For this reason, he has been accumulating poisonous gas in his body for years, until finally has reached a limit, and his own quirk begins to negatively affect his health. Takeshi ask the heroes, he is unsure if this makes him a villain.

Izuku wants to help him as Katsuki understands the situation. Katsuki figures Takeshi would feel better if he used his Quirk. Mirko is still cautious concerning the idea of helping someone whom she considers a villain, but Izuku convinces her that Katsuki wouldn't do this without a plan and that he trusts him. Ochaco believes in both her teammates when Mirko lets Katsuki take the lead. Takeshi is worried about using all of his dangerous Quirk, and Katsuki tells him to stop talking and just do it. Izuku tells him to trust them and reassures it with a smile.

Katsuki ask Ochaco to float Takeshi and himself as high as possible. As they continue to fly outward, Katsuki tells Takeshi to let it all out. Takeshi releases all the stored Poisonous Gas while Katsuki blows it up with his Explosion. Ochacho returns them to the ground. Feeling much better, Takeshi takes off his hood and cries with happiness, thanking everyone for helping him.

Due the gas that did escape while Takeshi was fleeing the heroes incapacitated several people, he was arrested by the police regardless. Luckily, Mirko's team talked to the police and explained the situation, being revealed onto the news. Thanks to this, many citizens were understanding and signed a petition to shorten his sentence.

Back at school, All Might ask his students how their first Team-Up Missions went and wants to hear the feedback. Class 1-A begins to ramble, and All Might tells them their next mission has already been decided. Izuku wonders who his next Team-Up Mission will be when he opens his envelope.