Japan's largest native breed, the Tosa Inu was developed in the late nineteenth century in Tosa, now Kochi Prefecture, by crossing local dogs with Western breeds such as the Mastiff, Bulldog, Great Dane and Saint Bernard. It was created for a ritualized form of dog fighting, and that history still shapes how many countries regulate it. Tosas have a short, dense coat, usually red, fawn, apricot, black or brindle, a broad head and a powerful, muscular frame.
Well-raised Tosas are often quiet, calm and deeply loyal to their family, but they tend to be wary of strangers and can be intolerant of other dogs. Their size and strength demand an experienced handler, early socialization, steady training and secure containment. Prospective adopters should also check local laws, housing rules and insurance policies before bringing one home.