According to the Koji-ki, an ancient chronicle of Japan, around 23 BC, a wrestler, Tomakesu-Hayato, was considered the most effective fighter of the age, but when he fought against Nomi-no-Sukune, by order of the emperor, he was defeated and kicked to death. Nomi-no-Sukune is considered the founder of "Jujitsu," the first true Japanese martial art.
Sumo was introduced into Japan from China in about 200 AD, near the end of the Han period. This was about the same time that the Japanese fighting style of "Chikara-kurabe" (which included kicking and hand techniques) originated as a brutal fighting method for training men preparing for war. Over the centuries, Chikara-kurabe evolved and became codified under the name "Kumi-uchi," which had restrictions on brutality. At the end of the Nara period (784 AD), body armor was coming into use on the battlefields, which made punching and kicking ineffective. Kumi-uchi was soon replaced with the more practical Jujitsu that used throws, arm locks, and strangles to circumvent the armor.
In 607 AD, the earliest recorded cultural exchange took place between Japan and China which lead to a great influx of Chinese into Japan who brought with them a form of soft Kempo methods, which blended with Jujitsu. Kempo (Ch'uan-fa) was introduced into Japan, between 1627 and 1644 AD, by Chen Yuan Ping, who also introduced the sai (two-prong sword), which the Japanese police later modified into a jitte-sai (one-prong sword). After taking refuge in a temple in Endo (Tokyo), he taught basic concepts that, after modifications and incorporation with other elements, were used by Jigoro Kano in his development of Judo, which excludes blows and strikes.