Can someone be a sumo without being Fat?

Could someone take up sumo wrestling, and compete, but not be fat. I know all sumos are over 300lbs, what If you wanted to be sumo but you want to stay lean, all muscle, would it be possible to train and get over 300+ lbs without getting fat like the Sumos, but instead be lean and purely muscle m? Im interested in sumo, but I am not fat, Im very muscular at 180 lbs(I know is small compared to sumos) Im 15 and have been lifting weights since I was 11. I want to compete in sumo when I get older But I dont want to get fat because it is very unhealthy. So how could I get as big as the sumo wrestlers without gaining any fat, but still be very large???