Teruo Unagisawa/Synopsis

Vigilantes Beginnings Arc
Teruo appears for the first time in a large congregation of fans of Pop☆Step, who had come to see her perform on the street. He tries to approach her, but the audience pushes him back, knocking him down. Ichimoku Samazu and Jube Namimaru help him and advise him that it is not okay to become obsessed with Pop☆Step.

However, desperate to touch his Idol, Teruo ignores them and injects Trigger, turned into a a eel-like Instant Villain who starts to chase a terrified Pop through the streets, asking her for a handshake. Koichi Haimawari and Knuckleduster try to stop him, but the mucus on his skin makes him slippery, making any of their attacks ineffective.

They draw a new plan, using Pop as bait. They manage to convince her to handshake Teruo, and while he is distracted, Koichi and Knuckleduster throw large quantities of flour to him, that drains all the liquid from the mucus. When losing his protective mucus, Knuckleduster gives him a beating and stops Teruo, being later arrested by the police.

The next day, Teruo is interrogated by the police to find out where he got the Trigger he used, but like almost all of the suspects who underwent villainification, he tells them that he received it from someone he does not know. Aware that they can not get much more information from him, the police decide to let him go without charges. When Teruo leaves the police station he reunites with Ichimoku and Jube and spends time with them, not knowing that he is being followed by Naomasa Tsukauchi.

But Kuin Hachisuka has other plans for Teruo. Kuin uses her syringe bees to dose an entire crowd with Trigger. In an instant an ordinary crowd of people turns into a horde of monsters with out-of-control powers, having to being stopped by several Pro Heroes. During the chaos and confusion caused by this outbreak, Teruo separates from his friends, meeting Kuin shortly after, who convinces him to accompany her.

Vs. Queen Bee Arc
After going missing for weeks, Teruo becomes almost unrecognizable, having been turned into a ginormous Next-Level Villain by the Villain Factory. Kuin visits the mutated Teruo, cunningly telling him that he will see Pop soon, exciting him.

Kuin decides to use Teruo to cause a big uproar in a concert in which Pop☆Step participates, with the intention of taking advantage of the disarray and dose more people with Trigger.

As he moves towards the concert, Teruo unleashes chaos through the streets, forcing Eraser Head to try to stop him before he causes further damage. Aizawa realizes that there is something strange about him: since he moves as if he was not used to such massive body, at first he thinks he has a transformation Quirk, and probably consumed Trigger. However, after checking that his Erasure does not affect him, realize that there is something else.

Whatever it is, Shota tries to stop him, and when his blows do not affect Teruo, he decides to retain him with his Capturing Weapon, but Teruo defends with a great electrical discharge that momentarily blinds Aizawa and causes a blackout throughout the neighborhood. Despite this unforeseen counterattack, Eraser Head manages to recover and ultimately defeat Teruo. However, Eraser Head notices a bee extracting samples from Teruo, but fails to capture it. As Teruo was being taken into custody, Eraser Head notices that Teruo wants to listen to Pop's concert, so he decides to watch over him until it's over, delighting Teruo.

Osaka Incident Arc
During the following days, Teruo would be heavily investigated by the police, who inform the Heroes that during the days he was missing, someone experimented with him, receiving numerous modifications to his body and being injected with large quantities of Trigger, making his transformation semi-permanent. Despite the problems he caused, Teruo is released and continues to attend Pop☆Step plays.

Sky Egg Arc
Teruo, Jube and Ichimoku attend a meeting discussing what merchandise to sell for Narufest, so they bring their fan expertise to help coming up for ideas. He later attends a Christmas party with the Narufest group and Captain Celebrity, as well as the latter's farewell party at the Tokyo Sky Egg.

Although Bomber villains attack the Sky Egg, the day is saved thanks to the efforts of Koichi, Captain Celebrity, All Might and other pro heroes. At the airport, Teruo and the Narufest group say their goodbyes to Captain Celebrity as he heads back to the United States.

Final Performance Arc
During the next two years, Teruo gets a part-time job as a waiter at Hopper's Cafe, and is unable to attend Narufest as frequently as before. One day, after Kirihito and Ikajiro rescue Koichi and Pop from two thugs, Teruo comes along to hand out flyers for their cafe. He later joins in a photo with the vigilantes and two girls they rescued.

Days later, Koichi goes to Hopper's Cafe to ask for help, as Pop has been missing for weeks. Teruo joins in to search for the idol, but to no avail. That night, however, Bee☆Pop emerges and bombs parts of Naruhata, leading to authorities labelling her a villain. When Bee☆Pop returned several days later, the Narufest group take shelter at the cafe, frustrated that they can't do more to help her.

Naruhata Lockdown Arc
The Narufest group meet again at Hopper's Cafe, discussing how Kazuho's condition is neither improving nor deteriorating. That night, Number 6 initiates his operation to sneak up on Kazuho's hospital and kill her, and cuts off power all over the neighborhood, inducing paranoia and fear in the civilians.