The Shikoku Ken is one of the six, native, Japanese sptiz-type dogs. Native to the mountainous region of the Kochi Prefecture on the Island of Shikoku, these athletic and agile dogs are accomplished big game hunters and are sometimes referred to as the Kochi Ken. Developed by the matagi (hunters in Japan that remained true to ancient traditions), the Shikoku Ken is prized for it's tenacity in face of large game and their relative calm around the family. Originally known as the Tosa Ken, they were renamed so as not to be confused with the Tosa Fighting Dog.

In post World War I Japan, the relative prosperity of the country succumbed to economic hardship as the Showa period began in 1926. Once relatively common, luxuries such as dog ownership became increasingly uncommon. In 1930, a study conducted by Japanese cynologist Haruo Isogai identified the six native japanese breeds: Shiba Inu, Hokkaido Inu, Kai Ken, Shikoku Ken, Kishu Ken, and Akita Inu. Further, Isogai grouped these six breeds into three categories based on size: small, medium, and large. The "Shika Inu", or medium-sized Japanese dogs, are the Hokkaido, Kai, Shikoku, and Kishu.

In 1928, the Nihon Ken Hozonkai (NIPPO) was formed. NIPPO is an organization dedicated to the preservation of the six native Japanese spitz-type dogs. The NIPPO founders initially focused their efforts on the Akita and the Shiba, but in 1937 NIPPO succeeded in having the Shikoku Ken declared a "Living Natural Monument" of Japan and a major reconstruction effort was undertaken.

Out of the reconstruction effort, three distinct lines of the Shikoku were developed: the Awa, the Hongawa and the Hata all named after the area they originated from within the Kochi prefecture. More recently the distinction between these lines has been blurred as remote areas where the dogs originated became easier to access and lines were cross bred. The modern Shikoku is thought to descend mainly from the Hongawa and Hata lines as the Awa line essentially disappeared as a result of the hardships caused by World War II and a lack of quality specimens due to cross breeding with outside dogs.

One of the foundation dogs of the Hata line was "Gomago," who was born in 1934. He obtained a Best in Show title in 1940. The principle elements of the Hata line included a generally heavier, stockier build and thicker, longer, and more profuse coats; skulls tended to be broader, ears tidier and smaller, and movement ponderous. Much of the Hongawa line is attribuatable to the foundation dog "Choushungo" who took best in show the following year and was also born in 1934. These dogs were characterized by light, flowing movement, long, strong limbs with excellent angulation, good ear set and correct eye colour. Their outer coats were harsh and weatherproof, but their protective undercoats did not match the quality of the Hata line. Hongawa Shikoku also tended to be slender and have a more elegant build. Ultimately it was the Hongawa Shikoku that was to have the most influence on the direction of the breed as we know it today. Two other notable Shikoku from the same period are "Kusugo" who took best in show in 1939 and "Kumago." These four dogs formed much of the foundation for the modern day Shikoku Ken. (Excerpted from here.)

The Shikoku standard, as written today, describes them as: "A medium-sized dog with well balanced and well developed clean cut muscles. It has pricked ears and a curled or sickle tail. Conformation: strong, well-boned and compact." Dogs are supposed to range from 19-21.5 inches at the whithers and bitches from 17-19 inches. Dogs weigh an average of 45 pounds and bitches closer to 35. There are four accepted coat colors in the standard: goma (sesame), aka (red), kuro (black), and shiro (white/cream). White is not desirable in the Shikoku and is penalized heavily in the conformation ring. For many years black was not popular with many breeders leading to the misconception that it is not desirable, however this is false. Many experienced Shikoku breeders in Japan will breed black Shikoku (especially males) to maintain darker colors and thicker coats in their blood lines. The black coloration was especially prevalent in the original Hongawa dogs. All Shikoku should have "urajiro" markings which are markings of a white or cream color presented on the ventral portions of the body and legs and cheeks and brow of the head. There are three types of goma (sesame): kuro-goma (more black than light colored hairs), aka-goma (red base with black hairs mixed in), and shiro-goma (white base with black hairs mixed in).

The Shikoku is more eager to please its owner than some of the other Nihon Ken, but is still an independent thinker and often will not listen or ignore commands. Shikoku can be territorial and make reasonable watch dogs, but are not by nature guard dogs or protection dogs. The Shikoku Ken is one of the rarest of the Nihon Ken. Only a small number are known to exist outside of Japan. Some estimates put this number around 100 (as of 2010). Even in Japan the breed is very rare with estimated annual registrations around 300-500. The total number of Shikoku Ken in Japan is estimated to be between 5,000-8,000.