Jizi, Qizi, or Kizi (), called in Korean Kija (), was a semi-legendary "Although Kija may have truly existed as a historical figure, Tangun is more problematical."

"The Tangun myth became more popular with groups that wanted Korea to be independent; the Kija myth was more useful to those who wanted to show that Korea had a strong affinity to China."

"If a choice is to be made between them, one is faced with the fact that the Tangun, with his supernatural origin, is more clearly a mythological figure than Kija." Chinese sage who is said to have ruled Kija Chosŏn in the 11th century BCE. Early Chinese documents like the Book of Documents and the Bamboo Annals described him as a virtuous relative of the last king of the Shang dynasty who was punished for remonstrating with the king. After Shang was overthrown by Zhou in the 1040s BCE, he allegedly gave political advice to King Wu,https://tspace.library.utoronto.ca/bitstream/1807/29740/1/Han_Hee_Yeon_C_201105_PhD_thesis.pdf p. 271 the first Zhou king. Chinese texts from the Han dynasty (206 BCE – 220 CE) onwards claimed that King Wu enfeoffed Jizi as ruler of Chaoxian (, pronounced "Chosŏn" in Korean). According to the Book of Han (1st century CE), Jizi brought agriculture, sericulture, and many other facets of Chinese civilization to Chosŏn. His family name was / () and given name was / (/ , or / ).

Kija (the Korean pronunciation of "Jizi") may have been the object of a state cult in sixth-century Goguryeo, and a mausoleum to him was established in Goryeo in 1102, but the first extant Korean text to mention Kija was the Samguk sagi (1145). Starting in the late thirteenth century, Kija was fully integrated into Korean history, being described as a successor to the descendants of Tan'gun in the state of Old Chosŏn. Following the spread of Neo-Confucianism in Korea in the fourteenth century, scholars of the Chosŏn period (est. 1392) promoted Kija as a culture hero alongside Tan'gun, with Kwŏn Kŭn's preface of Sambong chip writing,

However, with the development of radiocarbon dating and newly found excavations, modern Korean historians started to question the legitimacy of his enfeoffment as ruler of Old Chosŏn. Sin Ch'aeho (1880–1936) was the first to question the extent of Kija's cultural contributions and many followed as Kija's historical claims did not align with archeological evidence found during the time of his supposed rule. Additionally, post-war Korean scholars in both North and South Korea have strongly criticized the story of Kija's migration to Korea in the eleventh century BCE, claiming that his involvement in the history of Korea was widely exaggerated.

In recent times, both North and South Korea, and their respective historians do not officially recognize Jizi and his supposed accomplishments.

In ancient Chinese texts Pre-Qin sources The earliest known mention of Jizi is in the "Mingyi" hexagram of the Book of Change. According to other ancient Chinese texts like the Book of Documents, the Analects, and the Bamboo Annals, Jizi was a relative of Di Xin, the last ruler of the Shang dynasty, and one of the three wise men of Shang, along with Weizi () and Bi Gan.. Many identify him as Grand Tutor of the king. Jizi was either imprisoned or enslaved for remonstrating against King Zhou's misrule. (One later version states that he pretended to be mad after Bigan had been killed by King Zhou.). This version appears in the Huainanzi, a text that was compiled in the second century BC. After Shang was overthrown by the Zhou dynasty in the mid eleventh century BCE, Jizi was released by King Wu, to whom he gave advice on how to rule the new polity. Despite his victory, King Wu did not know why the Shang state fell, and upon asking Jizi why two years later, he was too uncomfortable to say. The Bamboo Annals records Jizi attending King Wu's court during the 16th year of his reign, not long before his death.

These texts mention neither Chosŏn nor Jizi's descendants; they simply describe Jizi as a virtuous man who was trusted by King Wu of Zhou after having been mistreated by the last Shang king.

Han and later texts The first texts that make an explicit connection between Jizi and Chosŏn date from the second century BCE, under the Han dynasty.. The earliest known source stating that Jizi went to Chosŏn is the (尙書大傳), a commentary on the Book of Documents attributed to Fu Sheng of the second century BCE. In that account, King Wu enfeoffed Jizi as the ruler of Chosŏn and Jizi became the subject of King Wu. In a similar story recorded in Sima Qian's Records of the Grand Historian (or Shiji, compiled between 109 and 91 BCE), Jizi was enfeoffed by King Wu but did not become his subject. Sima Qian did not mention Jizi in his section on contemporary Chosŏn (i.e. northwestern Korea), where Wei Man's kingdom had flourished since about 194 BCE until it was conquered by the Han dynasty in 108 BCE. Thus the location of Chosŏn as in these earlier sources is not clear. Among other Han dynasty sources, the Han shi waizhuan mentions to Jizi but not his migration to Chosŏn.

The "Monograph on Geography" (Dili zhi ) of the Book of Han (1st century CE) claims that Jizi had taught the people of Chosŏn agriculture, sericulture, and weaving, as well as proper ceremony.. Original text: (Hanshu [Book of Han], chapter 28.2, p. 1658 of the standard Zhonghua shuju edition). Jae-hoon Shim interprets the following sentence in that section of the Hanshu as claiming that Jizi also introduced the law of "Eight Prohibitions" () in Chosŏn.. Original text: (Hanshu [Book of Han], chapter 28.2, p. 1658 of the standard Zhonghua shuju edition). The Records of Three Kingdoms (late 3rd century AD) and other later documents interpret these "Eight Prohibitions" as Jizi's teachings, but it is also possible that the Hanshu was describing the early phase of Lelang Commandery, and not Jizi's initiatives. The Records of Three Kingdoms (first published in the early fifth century) claims that the descendants of Jizi reigned as kings of Chosŏn for forty generations until they were overthrown by Wei Man, a man from the state of Yan, in 194 BCE.. Record of Three Kingdoms (chapter 30, p. 848): . The overthrowing of the kings of Joseon by Wei Man is also recorded in the Brief History of Wei (third century), which is cited in Sanguozhi, chapter 30, p. 850.

According to his commentary to the Shiji, Du Yu (first half of the 3rd century) states that the tomb of Jizi was located in Meng Prefecture of the State of Liang (modern-day Henan). This suggests that the story of Jizi's association with Chosŏn was not necessarily prevailing although the narrative seen in the Hanshu later became common.

As historian Jae-hoon Shim concludes, only during the Han dynasty (206 BCE – 220 CE) did Jizi begin to be associated with Chosŏn, and only after the Han were his descendants identified as the Chosŏn royal family.

Possible Oracle Bone mentions Oracle bones excavated in Yin during the 20th century led to significant development in interpretations of traditional Chinese historiography. Li Xueqin speculates that a ruler of the Qifang during the Late Shang period could be identified with Jizi on palaeographical grounds, but this has been disputed, chiefly on the basis of zi () being interpreted as a name, not a title.

Interpretations Ancient Korean accounts The first extant Korean text to mention Kija (the Korean pronunciation of Jizi) was Kim Pusik's Samguk sagi (completed in 1145), which claimed that Kija had been enfeoffed in Haedong (: Korea) by the Zhou court, but commented that this account was uncertain because of the brevity of the sources.. Only in the thirteenth century did Korean texts start to integrate Kija more fully into Korean history. The Samguk yusa (1281) explained that after being enfeoffed by King Wu of Zhou, Kija replaced Tan'gun's descendants as the ruler of Chosŏn, whereas Jewang Ungi (1287) identified Tan'gun and Kija as the first rulers of former and latter Chosŏn respectively. Most premodern Korean historians after that accepted that Kija had replaced another indigenous power (represented by Tan'gun) in Old Chosŏn.

In 1102, during the Goryeo period, King Sukjong built a mausoleum to Kija in a place near Pyongyang that had been identified as Kija's tomb., citing the Goryeosa, the official history of Goryeo compiled in the fifteenth century under the Joseon period.Sadang for Kija called Kijasa () was also built in Pyongyang. The mausoleum was rebuilt in 1324 and was repaired in 1355, but the cult of Kija spread most widely after the establishment of the Chosŏn Dynasty in 1392. Because Chosŏn's state ideology was Neo-Confucianism borrowed from China, Chosŏn intellectuals promoted Kija as a culture hero who had raised Korean civilization to the same level as China..

From the second half of the sixteenth century to the eighteenth century, Chosŏn scholars published a number of books on Kija. In 1580, Yun Tusu collated all available material on him and published his research as the Kijaji (; "Record of Kija"). On the same year, eminent scholar Yi I used Yun's book to compile the Kija Silgi (), or True Account of Kija. Yi praised Kija for introducing agriculture, sericulture, decorum, the well-field system, and the Eight Prohibitions. Though he emphasized Kija's independence from King Wu of Zhou, Yi believed that Kija's teachings helped Korea to reach the same level of civilization as China.. The cult of Kija also continued as temples which worshiped Kija portraits called Kijayeongjeon (), were built in the 18th century in South Pyongan Province.

Although Korean scholars became more critical of Kija's role in the eighteenth and nineteenth centuries, this account of Kija as the "bearer of civilization from China" became widely accepted, so much that by the late Chosŏn, the worship of Kija "had become an integral part of Korean cultural identity."Historians more critical: , citing . Kija as "bearer of civilization: , pages 37 ("Korean transmission from the sage Kija at the founding of civilization in Korea") and 43 (Kija as "the bearer of civilization from China"); and . "Integral part of Korean cultural identity": . Some Korean clans claim to be direct descendants of Kija himself.. These families were the Han () of Sangdang , the Ki () of Deogyang , and the Seonu () of Daewŏn .

Twentieth century accounts In the beginning of the twentieth century, Korean historians started to doubt the authenticity of his supposed influence. Sin Ch'aeho (1880–1936), a Korean independence nationalistic activist historian during the Japanese occupation, was the first to question the extent of Kija's contributions. In an essay titled Doksa Sillon ("New Reading of History"; 1908), he argued that Korean history was revolved around Tan'gun, the legendary founder of the state of Old Chosŏn.. Sin dismissed Kija's contributions due to his foreign origin. Sin also argued that Kija had become a vassal of the kings of Buyeo and was only given control of a small territory..

Other historians such as Choe Nam-seon (1890–1957) and Lee Byeong-do (1896–1989) started to notice discrepancies between pre-Qin Chinese records of Jizi/Kija, and later accounts (both Chinese and Korean) of his role in Chosŏn. In 1973, archeologist Kim Cheong-bae () denied Chinese influence on Korea because no ancient Chinese bronzes had been found on the peninsula..

In addition, Ri Chirin, a leading North Korean historian of ancient Korea, argued that the Kija legend had been forged in Han times when the Chinese started to occupy part of Chosŏn. Most North Korean scholars have followed Ri in doubting the authenticity of Kija's migration to Chosŏn..