According to the
Kojiki, he became a king over part of
Korea which is speculated to be near the
Kaya confederacy. However, according to the
Shinsen Shōjiroku, it is stated that he and the kings of
Silla shared the same lineage. The kings or their lineages were never specified. The authenticity of the claim is considered vague and obscure as the record does not specify a name or a dynasty of which the Japanese god became the ancestor to the kings of Silla. However, it is quite likely that the book is alluding to Silla kings who were indeed of Japanese descent such as
Talhae of Silla (though the claim is sometimes disputed) and the grandchild of
Heulhae of Silla, who was born from the daughter of Heulhae and the prince of Japan (believed to be the son of
Ugayafukiaezu) in 312 CE. Interestingly, it is said that Inahi no Mikoto was one of the four sons of Ugayafukiaezu, and with the claim stating that Inahi was the ancestor to the kings of Silla, it can be speculated that Heulhae's grandson was Inahi no Mikoto's child. However, these are historical sources found only in Korea and not in Japan. Moreover, Heulhae's line (the
Gyeongju Seok clan) ended with his successor,
Naemul of Silla, who was a
Gyeongju Kim clan, which makes the claim of the ownership of the kings of Silla after Heulhae questionable as they descended from different families. Due to the lack of historical evidence found in Japan, modern Japanese scholars began cross-referencing other sources that may act as a bridge to the claim found in the
Shinsen Shōjiroku. According to historian
Takehiko Furuta, a legendary Japanese sword called "''
(天羽々斬; あめのはばきり)" had an alternate name called "Orochi no Karasahi
(蛇之韓鋤; をろちのからさひ)"; he posited that "Karasahi
(韓鋤)" was most likely a loanword from Korean as "Kara (韓)" meant "Korea" and "hi (鋤)" meant "to cut", deriving from the native Korean verb "bi- (비-); be- (베-)" which also means "to cut". Similar observation was made by Furuta on the name "Masahi (馬射戲; まさひ)", a traditional Japanese horse-riding archery event that has roots in the kingdom of Goguryeo, pointing out that the "hi" found in "Masahi" shares the same sentiment found in "Karasahi''". Mishina posited that King Dongmyeong's founding story aligned closely with Inahi no Mikoto's own background; that due to the stories surrounding Inahi no Mikoto and Korea (Silla and Goguryeo) were very similar in nature, he stated that the two were clearly related. His argument was incorporated into the
Nissen dōsoron. == Genealogy ==