The Kai Ken (甲斐犬, also called the Tora Inu or Tiger Dog?) is a breed of dog that hails from Japan where it is a national treasure and has been bred for centuries. It is an extremely rare dog even in its native land and is related to the Spitz dog type.
The Kai Ken is a medium sized dog with a wedge shaped head and prick ears. Males are typically 18 to 22 inches at the shoulder, while the females are slightly smaller, 17 to 20 inches at the shoulder. The tail may be curled over the back, or carried in a sickle position. Limbs should be strong and hocks should be well developed reflecting the dogs’ history of mountain life. The coat is of harsh texture, medium length, and black or brindle in color. Its coat could be red or black at the "background". The red is the Aka-tora, the black is the Kuro-tora and between them, the Chu-tora.
The Kai Ken is intelligent, agile, alert and brave. They are naturally hunters and make good guard dogs, being reserved with strangers but loyal to their families. They are friendly, often good with children and are not usually aggressive towards other dogs.(Wikipedia)