Goto Imasuji, also known as Muscular, later Jailbreaker, is a minor antagonist in the manga/anime series My Hero Academia. He is a villain affiliated with the League of Villains and a member of the organization’s Vanguard Action Squad. He serves as one of the main antagonists of the Forest Training Camp Arc and a minor antagonist in the Paranormal Liberation War Arc.

He is a sociopathic madman who is responsible for the deaths of the Pro Hero team, Water Hose. The battle left him with an enormous scar on the left side of his face. As a result, he received an artificial eye to cover the wound, as well as receive replacements, if the original were to be damaged or lost.

He is voiced by Kosuke Takaguchi in the Japanese version of the anime, Lee Seung-Haeng in the Korean dub and Jim Foronda in the English dub.