Atsushi is basically that guy who shows up in episode 22A of Osomatsu-san as one of Todomatsu's acquaintances. His whole thing is that he owns a car, which apparently makes him way too much of a threat. Todomatsu actually considered inviting him to a mixer but realized Atsushi would just steal all the girls, so that plan got scrapped pretty quickly.
Beyond that single episode, there's not much to him. He's popped up as a background character on some merchandise like keychains, but honestly, nobody knows anything about the guy except that he's got a car and a name. Fans don't have much to work with here.
Content compiled by AnimeList.moe from publicly available sources.
