Yosetsu Awase/Synopsis

History
Yosetsu was raised in a small town factory.

Entrance Exam Arc
While he doesn't appear during the events of the arc, he manages to rank 10th in the exam, with 50 villain points and six rescue points.

U.A. Sports Festival Arc
Yosetsu finishes the Obstacle Race at 12th place, allowing him to continue onto the next event, the Cavalry Battle. He forms a team with Tetsutetsu Tetsutetsu, Juzo Honenuki, and Ibara Shiozaki.

At the beginning of the event, Tetsutetsu's team attacks Izuku Midoriya's team with Juzo using his Quirk to trap them, but Izuku uses his jetpack to escape. Tetsutetsu's team attacks them again, but Fumikage Tokoyami's Dark Shadow blocks them off. After the Cavalry Battle ends, Tetsutetsu's team fails to qualify for the final event. Tetsutetsu is confused as to how they lost all their points and Ibara remarks that it is possibly punishment for taking Minoru Mineta's headband in such an unfair way.

Although they lost, they are offered the chance to participate in the tournament, because Mashirao Ojiro and Nirengeki Shoda request withdrawal, and Itsuka Kendo gives the opportunity to fill their positions to Team Tetsutetsu because she thinks they deserve it more because they fought harder during the Cavalry Battle. Juzo and Yosetsu decide that Tetsutetsu and Ibara are the ones to participate, something they are very grateful for.

Forest Training Camp Arc
When Class 1-B arrives at the training camp, their homeroom teacher explains that they will be extending their Quirks and that the more they use their Quirks, the stronger they will be by breaking their limits. When Class 1-B witness Class 1-A's training, Yosetsu is taken by surprise. The Wild, Wild Pussycats appear to explain that they will be there to help and guide them in their training.

During the third day, the Vanguard Action Squad attacks the camp, filling the forest with gas and fire. Yosetsu runs into Momo Yaoyorozu who created gas masks to avoid inhaling Mustard's poisonous smoke. They meet Tetsutetsu and give them a few masks before continuing on their way to help others.

They are attacked by the Chainsaw Nomu, which injures Momo. Yosetsu carries her while running away from the Nomu, which cuts several trees down with its multiple weapon arms consisting of chainsaws, drills, and hammers. Momo apologizes to him for dragging his speed down.

The Nomu reaches him and is about to attack him with one of its weapon arms. Suddenly, its chainsaw arm stops and it retracts its weapon arms into its body and begins walking back to the Vanguard Action Squad's rendezvous point. Momo realizes that it is being called back because the villains have captured Katsuki Bakugo. Thinking of a plan, she creates a tracking device and asks Yosetsu to weld the button onto the Nomu. He runs after it and bonds the device onto the Nomu's back. As it walks away, Yosetsu and Momo decide to continue running.

Shie Hassaikai Arc
Neito Monoma reveals that all of class 1-B have passed the Provisional Hero License Exam.

Yosetsu is one of the few Class 1-B students who participates in the Hero Work-Studies.

U.A. School Festival Arc
For the School Festival, Class 1-B decides to perform a play, in which Yosetsu is one of the main actors. While carrying a props dragon along with Neito and Tetsutetsu, they intersect with Izuku Midoriya, who was showing Eri the school together with Mirio Togata.

When Neito starts trash-talking Izuku and Class 1-A, he whacks him with a board to stop him. He apologizes to Izuku, Eri and Mirio Togata for Neito's behavior and explains to them that Itsuka wasn't around because she was forced to enter the Beauty Contest.

Yosetsu later makes a comment about either Itsuka or her dress looking sexy. He takes part in Class 1-B's play.

Joint Training Arc
Eraser Head & Vlad King decide to organize a competition between their respective classes. Yosetsu along with the rest of Class 1-B are pitted against Class 1-A as part of the Joint Training Battle. He is placed in the fourth round of match-ups, teaming up with Setsuna Tokage, Kojiro Bondo, and Togaru Kamakiri against Katsuki Bakugo, Kyoka Jiro, Hanta Sero and Rikido Sato.

As the fourth match starts, He and Kojiro tells his teammates that Class 1-A has the perfect balance between offense and defense and that if they lag behind they are done for. Setsuna declares that the first team to make a move wins and tells her team to advance.

The class 1-B team ambushes the rival team, but their plan fails and they have to withdraw, being chased by Katsuki who wants to get an absolute victory. Yosetsu stays hidden in the shadows and ambush Katsuki. Combining his stealth skills with his Weld Quirk handling to effectively subdue the powerful Katsuki Bakugo, welding him to a pole with his Ultimate Move Construction-Done-Kwik: Weldcraft However, Rikido saves Katsuki with Sugar Rush. Now free, Katsuki continues his chase.

Yosetsu makes an armor to protect himself in preparation to withstand Katsuki's assault. To his surprise, he decides not to attack him. Instead, Katsuki ignores him and flies towards Kojiro, letting Kyoka attack him with sound waves that get amplified by the armor he intended to block the explosions with. Yosetsu is later seen tied up in tape by Hanta. Soon, his teammates will also be defeated and captured.

After the absolute victory of a Class 1-A team in the fourth match, he can be seen with his teammates lamenting their humiliating defeat.

With the match over, Yosetsu watches the remaining rounds along with the rest of the students. The Joint Training Battle ends with victory for class 1-A. Despite the fierce competition and the result, the exercise ends on good terms between both classes, and later Class 1-B visits Class 1-A's dormitories for socializing and dinner.

Endeavor Agency Arc
With the start of the second Hero Work-Studies, he teams up with Hiryu Rin.