Kim Chung-seon born Sayaga and often known by his pen name Mohadang, was a Japanese general who defected to Korea during the Japanese invasion. However there is no proof a person by this name ever existed in Japan. More importantly the name "Sayaga" could not be a samurai name. Some theories suggest Sayaga to be a Korean misinterpretation of Saika, referring to the Saika Shu. This once again has no historical basis, and is simply based on the similarity of names. An important note is that the Saika Shu were commanded to remain at Nagoya castle by Hideyoshi and never entered Korea.

Kim Chung-seon is said to have been the commander of the right army for Katō Kiyomasa

Kato Kiyomasa

was a Japanese daimyō of the Azuchi-Momoyama and Edo period.-Origins and early career:Kiyomasa was born in Owari Province to Katō Kiyotada. Kiyotada's wife, Ito, was a cousin of Toyotomi Hideyoshi's mother. Kiyotada died while his son was still young...

, leading more than 3,000 troops. He defected shortly after arriving on Korean soil, surrendering to Gyeongsang

Gyeongsang

Gyeongsang was one of the eight provinces of Korea during the Joseon Dynasty. Gyeongsang was located in the southeast of Korea....

 commander Pak Jin. This choice has been traditionally attributed to his respect for Korean culture. This has not been confirmed, as there is no record of a Sayaga or Sayaka within the available documentation regarding Kiyomasa's troops.

After his defection, Kim served in the Joseon army, contributing to Korean victories over Japanese forces in the battles of Dongnae and Ulsan. Thereafter he was granted his Korean name, on the recommendations of Gwon Yul

Gwon Yul

Kwon Yul was a Korean Army General and the Commander-in-chief of the Joseon Dynasty, who successfully led the Korean forces against Japan during the Japanese invasions of Korea...

 and others, and was made part of the Gimhae Kim lineage.

Kim continued his military service after the end of the Japanese invasions in 1598, working for 10 years on securing the northern border. He fought the rebellion of Yi Gwal

Yi Gwal

Yi Gwal was a general during the Joseon Dynasty, Korea. His family belonged to the Gosung Yi clan.Perhaps he is best known for his rebellion against the government of King Injo in 1624, but prior to that date, he was a very able and brilliant commander.-Background:In 1622, he joined the Injo...

 in 1624, personally capturing Yi's lieutenant Seo A-ji (서아지 / 徐牙之). In 1636, he participated in the defense against the Second Manchu invasion of Korea

Second Manchu invasion of Korea

The second Manchu invasion of Korea occurred in 1636, when the Manchu Qing Empire brought Korea's Joseon dynasty into submission. It followed the first Manchu invasion of Korea of 1627.-Background:...

, credited with the death of some 500 Qing troops at the battle of Ssangnyeong.

After Joseon's surrender to the Manchus, Kim retired from military life, moving to Daegu

Daegu

Daegu , also known as Taegu, and officially the Daegu Metropolitan City, is a city in South Korea, the fourth largest after Seoul, Busan, and Incheon, and the third largest metropolitan area in the country with over 2.5 million residents. The city is the capital and principal city of the...

 where he married the daughter of the mok commander Jang Chun-jeom (장춘점 / 張春點). They settled in present-day Urok-ri, Gachang-myeon

Gachang-myeon

Gachang-myeon is a myeon, or township in rural southeastern Daegu, South Korea. Part of Dalseong County, it is separated from the urban center of Daegu by the ridgelines of Yongjibong and Apsan. These two mountains are separated by the narrow valley of the Sincheon, a tributary of the Nakdong...

, Dalseong-gun

Dalseong-gun

Dalseong-gun or Dalseong County is a gun occupying much of south and western Daegu, South Korea. A largely rural district lying along the Nakdong River, it makes up nearly half of Daegu's total area...

. Kim devoted himself to Confucian ethics, promulgating gahun (family principles) and hyangyak (village creed).

The Nokdong Seowon in Urok-ri was erected in his memory in 1789. This seowon

Seowon

Seowon were the most common educational institution of Korea during the mid- to late Joseon Dynasty. They were private institutions, and combined the functions of a Confucian shrine and a preparatory school. In educational terms, the seowon were primarily occupied with preparing students for the...

 was abolished in 1864 as part of the regent Daewon-gun

Daewon-gun

Heungseon Daewongun or The Daewongun , or formally Heungseon Heonui Daewonwang and also known to period western diplomats as Prince Gung, was the title of Yi Ha-eung, regent of Joseon during the minority of King Gojong in the 1860s and until his death a key political figure of late Joseon...

's general campaign against seowon, but was reestablished in 1914 under the Japanese colonial regime

Korea under Japanese rule

Korea was under Japanese rule as part of Japan's 35-year imperialist expansion . Japanese rule ended in 1945 shortly after the Japanese defeat in World War II....

. The seowon remains a popular destination for Japanese tourists in Daegu.

Kim's 6th-generation descendants compiled his collected works, which exist in two editions.