First of all if you are in a situation where you constantly have to defend your life, figure some stuff out and fix it. If you are depending for any dog to save your life you are a dumbass. If anyone is going to kill me they are not going to do it with thier bare hands and a gun will defeat any dog in less than a second. Second, Japan is the safest country Earth with almost zero violent crime rate. The socio-economic conditions create a guard dog do not exsist in Japan. The Akita (JA) was created originally as a hunting and all porpouse farm dog. For th last sixty years it has exsisted as a show dog, companion dog for the highest class. The Tosa is a dog of the Yakusa. Yakusa do not have to worry about street crime and if one where to get whacked, the type of dog will mak no differance. The Tosa has to be handled in the heat of combat by many people, stranger, friend or different. Human agression would cause a problem in that arena The American Akita has traditionally had more of a defensive nature than the Japanese breed, but that is result of American desires in a breed, not the Japanese.