The Kai Ken (甲斐犬, Kai-ken, Kai-inu[1], also called the Tora Inu or Tiger Dog) is a breed of dog native to the Kai region, Yamanashi Prefecture, Japan,[2] where it is a national monument. It is a rare dog even in its native land and is one of the six native Japanese dog breeds protected by the Nihon Ken Hozonkai.[3]