The Tosa, also called the Tosa Inu or Japanese Mastiff, is a breed of dog of Japanese origin that is considered rare. It was originally bred in Tosa as a fighting dog and still is today. Other names of this breed include Tosa Ken, Tosa Token, Japanese Fighting Dog, Tosa Fighting Dog, and Japanese Tosa. Check out our collection of Tosa Inu dog names for male or female puppies.