Yosetsu Awase, also known as Welder, studies in Class 1-B at U.A. High School. Raised in a small factory town, this background fostered his resourcefulness and practical approach to hero work. His Weld quirk fuses objects together at the atomic level upon direct physical contact with both targets, making it highly effective for restraint or repair. He carries steel logs as part of his hero costume to extend his quirk's range, allowing him to bridge objects without needing simultaneous touch. His ultimate move, Construction-Done-Kwik: Weldcraft, rapidly binds opponents to structures using these metal logs. Awase has long black hair spiked upward and backward, usually held by a blue-and-white zigzag-patterned headband. His eyes are rounded, gray, and tilt inward. His burgundy full-body hero suit features a high collar, layered chest armor, dark brown shoulder pads, and white knee-high boots with brown accents. Utility belts hold bags containing materials like wood and metal blocks to support his quirk. He ranked 10th in the U.A. Entrance Exam with 50 villain points and 6 rescue points. At the U.A. Sports Festival, he placed 12th in the Obstacle Race, showcasing athleticism despite his quirk lacking mobility benefits. He joined Team Tetsutetsu for the Cavalry Battle but did not advance to the tournament. During the Forest Training Camp attack by the Vanguard Action Squad, Awase discovered an injured Momo Yaoyorozu after her encounter with a Chainsaw Nomu. He carried her to safety while evading the Nomu, refusing to leave her despite the danger. When the Nomu paused, Yaoyorozu created a tracking device which Awase welded onto the creature. This tracker later helped heroes locate the villains' hideout, aiding in Katsuki Bakugo's rescue. The experience caused Awase lingering trauma, resulting in nightmares and a fear of loud mechanical noises like chainsaws. He passed the Provisional Hero License Exam and engaged in Hero Work-Studies with Hiryu Rin. In the Joint Training Battle against Class 1-A, Awase was on the fourth match team opposing Katsuki Bakugo. He initially subdued Bakugo using Weldcraft but was countered by Rikido Sato. Awase then crafted defensive armor against Bakugo's explosions, but Kyoka Jiro amplified her sound waves through the metal, leading to his capture and his team's loss. At the U.A. School Festival, Awase helped with Class 1-B's play, carried props, and intervened when Neito Monoma antagonized Class 1-A. He expressed admiration for Itsuka Kendo's appearance during preparations. Following the Paranormal Liberation War, he continued his studies and training. Eight years after the Final War, Awase graduated from U.A. and became a professional hero. His personality shifts from foul-mouthed terseness in casual settings to heightened talkativeness during crises. He exhibits selflessness, prioritizing others' safety over his own during the Chainsaw Nomu attack. Confident in his quirk, he avoids deep class rivalries, apologizing for Monoma's behavior and collaborating openly with Class 1-A members. He enjoys mobile games and maintains a pragmatic outlook shaped by his working-class roots.