One of the six native breeds of Japan, the Shikoku Ken, previously known as the Kochi Ken, originated in the mountainous island region of Shikoku, as its name suggests. Due to the remoteness of the area, Shikoku remained largely isolated not only from other breeds but from each other which contributed to purity within the breed as well as led to the development of five distinct lines. Those lines are know as the Iya and Kochi-Aki - the Eastern strains - and the Hata, Hongawa, and Awa - the Western strains.
While some of these lines naturally combined over time, others disappeared due to various hardships, like the Awa after World War II. Today, most modern shikoku can trace their lineage back to either the Hata or Hongawa strains. Hata dogs were notably stockier with broader heads and small, tidy ears as well as thicker and longer coats. Hongawa dogs, by comparison, were considered more slender with lighter, more refined movement.
Japanese hunters, the Matagi, greatly prized the Shikoku for their fierce hunting abilities. They were trained in two hunting styles - Hoeru-dome (吠える) or barking to detain, and Kami-dome (噛み切る) or biting to detain. Hunters largely favored the former as it posed less risk to the dogs. As a result of the region in which they were developed, Shikoku are perfectly suited for navigating rough and mountainous terrain, and are adept jumpers and climbers - a fact which also makes them excellent hiking companions.
In 1928, the Nihon ken Hozonkai (Japanese Dog Preservation Society) was formed. Referred to as NIPPO, the society is dedicated to the preservation of the six native Japanese breeds - the Shiba, Shikoku, Kishu, Kai, Hokkaido, and Akita, with the Shikoku having been declared a Living Natural Monument in 1937.
Today, the Shikoku is described, per the standard, as a medium-sized dog with well balanced and well developed clean cut muscles. It has pricked ears and a curled or sickle tail with overall conformation giving the appearance of a dog that's strong, well-boned, and compact. Furthermore, the Shikoku is a dog of marked endurance, keen in sense with a naive feeling, energetic and highly alert; an enthusiastic hunter; docile towards his master.