The Tosa's most striking physical characteristic is its large head and deep, broad chest. Tosas may develop black muzzles and ears. Dogstar's males average 140 to 170 pounds, while females average 110 to 140 pounds, though these dogs may appear larger due to their muscular builds.
The heavyweight Tosa is a massive, large boned and athletic dog with surprising agility for its size. They maintain their muscular physique with a minimum of space and exercise. They are a massive, well built dog. Unlike other large breeds, Tosas are very agile, even as they grow older, and they are not excessive droolers. In comparison to other larger breeds, they are long lived and require much less space. Tosas are generally very calm.

DogStar breeds the true red Tosa. Pups vary from a fawn to a dark red, and some have white coloring on the paws and chest.