The was an ancient trade route in Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 that is now mirrored by the modern National Route 33. It was first established during the Yamato period

Yamato period

The is the period of Japanese history when the Japanese Imperial court ruled from modern-day Nara Prefecture, then known as Yamato Province.While conventionally assigned to the period 250–710 , the actual start of Yamato rule is disputed...

, was then developed into an official highway during the Meiji period

Meiji period

The , also known as the Meiji era, is a Japanese era which extended from September 1868 through July 1912. This period represents the first half of the Empire of Japan.- Meiji Restoration and the emperor :...

, before being renamed the Prefectural Matsuyama

Matsuyama, Ehime

is the capital city of Ehime Prefecture on the Shikoku island of Japan. It is located on the northeastern portion of the Dōgo Plain. Its name means "pine mountain." The city was founded on December 15, 1889....

-Kōchi

Kochi, Kochi

is the capital city of Kōchi Prefecture on Shikoku island of Japan.Kōchi is the main city of the prefecture with over 40% of its population. As of May 31, 2008, the city had an estimated population of 340,515 and a density of...

 Highway (県道松山高地線 Kendō Matsuyama-Kōchi-sen). On January 18, 1945, it was established as National Route 23

Japan National Route 23

National Route 23 is a national highway connecting Toyohashi, Aichi and Ise, Mie in Japan.-Route Data:*Length: 175.3 km *Origin: Toyohashi *Terminus: Ise...

, before becoming National Route 33 on December 4 of the same year.

The Tosa Domain

Tosa Domain

The was a feudal domain in Tosa Province of Japan during the Edo period. Its official name is . Some from the domain played important roles in events in the late Tokugawa shogunate...

 used a route that connected Kōchi with the modern-day Shikokuchūō

Shikokuchuo, Ehime

is a city located in Ehime, Japan.Shikokuchūō is the leading producer of paper and paper products in Japan. It is also a port city and one of Ehime’s major centers of industry....

 sankin kōtai

Sankin kotai

was a policy of the shogunate during most of the Edo period of Japanese history. The purpose was to control the daimyo. In adopting the policy, the shogunate was continuing and refining similar policies of Toyotomi Hideyoshi. In 1635, a law required sankin kōtai, which was already an established...

. This route was called the "Old Tosa Kaidō" (旧土佐街道 Kyū-Tosa Kaidō).