Mr. Osoi is a humanoid sloth, and is part of the leaderless villain group, the Coalition of Five. He appears to be in his late 50s, although Mr. Osoi is actually only 28, the aging is a side-effect of his quirk. He’s quite a character and is easily entertained, and is far more child-like and humorous than his aged appearance would suggest - however, Mr. Osoi's quirk is incredibly powerful (it allows him to manipulate the rate of change [movement speeds] of people/objects in small radius) and he is serious when he needs to be.