Death Arms/Synopsis

History
In a meeting with other Pro Heroes and a member of the police force to discuss the unwilling civilians injected with Trigger, the police officer explains that the people in question were more victims than villains. Endeavor argues that any public use of a Quirk is illegal and that they should treat them as villains and let the police investigate the backgrounds of future captures. He said this is the only way to protect the innocent while not risking themselves through hesitating every time they see a new enemy. All Might, who was not present, has his reply to the problem delivered by Naomasa Tsukauchi. He states that he would assess the situation at the scene more carefully because as heroes, they must not bring harm to innocent citizens.

Entrance Exam Arc
Death Arms guides civilians out of the area while other heroes are fighting a Giant Villain.

Later on, Death Arms is among the heroes who are trying to stop the Sludge Villain who is controlling Katsuki Bakugo but he cannot do anything since the villain is too fluid. None of the heroes who are present can do something against the villain and Death Arms clenches his fist in anger. As he and the other heroes wait for a hero who is able to hurt the villain, Izuku Midoriya tries to help Katsuki.

Death Arms tries to stop him but Izuku does not listen to him. All of the Heroes then try to help him, but before they can do anything, All Might defeats the villain with one attack. Death Arms and the other heroes then clean the area. He later scolds Izuku for his actions since he could have been killed.

U.A. Sports Festival Arc
Having been assigned as security, Death Arms, Kamui Woods, and Mt. Lady are seen outside U.A. High School's Sports Festival Stadium. Kamui Woods and Death Arms originally wanted to scout for talented individuals but they are not able to do that because of the guard duty.

During the obstacle course of the festival, Death Arms spots Izuku Midoriya, the young man who purposely got himself involved with a villain and was amazed by his progress.

Later, after the rules of the Cavalry Battle have been explained, Death Arms, Kamui Woods, and Mt. Lady are in the break room and start discussing the U.A. Sports Festival. Death Arms says that the Sports Festival is all about preparing the young heroes for the real world of heroes and that the Obstacle Race was a way of showing that you need to kick down others to show what you are able to do. Mt. Lady, after mentioning that she feels bad about having done that to Kamui Woods, mentions that Heroes need to work together in order to accomplish a goal and the Cavalry Battle is a good representation of that.

Vs. Hero Killer Arc
Kyoka Jiro choses doing the Hero Agency Internships with Death Arms. The hero works out Kyoka hard in the field. He makes her run during patrol and she barely keeps up with him. Kyoka thinks to herself about much harder her training is compared to school.

Later, Kyoka helps Death Arms rescue civilians from a hostage situation. She uses her Quirk to figure out how many hostages were taken. Kyoka escorts them both to safety after Death Arms rushes in.

Pro Hero Arc
When Hero Billboard Chart JP announcement is made, Mt. Lady was interviewed and cried as she ran to Death Arms for comfort about Kamui receiving recognition. He remarked that she was amazing in her own right.