Achi no Omi
Achi no Omi also known Achikishi as well as Achiki or Achi no Ō, was the legendary founder of the Yamatonoaya clan, an immigrant clan in ancient Japan who hailed from the kingdom of Paekche with his son . He is not to be confused with another individual named " " found in the Nihon Shoki.
He is considered one of the three most influential Toraijins alongside Yuzuki no Kimi and Wani during the Kofun period.
History
Originally from the kingdom of Paekche, he is first mentioned in the Kojiki as a stable master who took care of the horses brought over from Paekche.He is later mentioned again in the Nihon Shoki when discussing about his arrival in Japan. It parrots the same reason for his immigration to Japan from Paekche, but this time, under two different variations of his name: Achiki and Achi no Omi.
He has three descendants depending on the source: Achishi or Achi no Fumi, Achikishi, and Tsuka no Omi. It is unclear if all of them are related to one another, despite having names that sound similar. Interestingly, one of the descendants, Achikishi, possess the same pronunciation of Achi no Omi's oldest name, Achikishi, but under different characters and titles.
Origin
Due to conflicting details across several sources that claim different origins of Achi no Omi, several theories have been proposed by modern historians.In the earliest accounts such as the Kojiki and the Nihon Shoki state that Achi no Omi and his clan had originated from the kingdom of Paekche.
However, according to Shoku Nihongi, it is said that he was the great-grandson of Emperor Ling of Han which is the reason why his clan was named "東漢" meaning "Eastern Han" in Chinese characters. In contrast, according to the claim made by the Sakanoue clan, Yamatonoaya's cadet branch clan, Achi no Omi was a descendant of Emperor Xian of Han being either his grandson or great grandson and not Emperor Ling in the Shinsen Shōjiroku. These claims made by blood relatives conflict with each other causing genealogical confusion among modern historians.
It is very likely that the added information and claims are aggrandizations made by the authors to emphasize the clan's importance as older sources do not mention anything about Achi no Omi being related to Chinese royalty. According to historian, it was common for Korean descendants to rely on prominent families for their lineage in order to raise their social status.
Modern Japanese scholars have indicated that Yamatonoaya clan and other "Aya " clans were all related and that they were generally classified under the same ethnic group. These mainly included: the Aya clan, the Ayahito clan, the Yamatonoaya clan and the Kawachinoaya clan. It is said that Yamatonoaya clan, Aya and Kawachinoaya, though not from the same founder, were ethnically related, most likely all immigrating from Paekche.
| Source | Year | Claim |
| Kojiki | 712 | Written under "Achikishi ", he was sent to Japan from Paekche and suggested/introduced Wani to the Yamato kingship as a fellow mentor. |
| Nihon Shoki | 720 | Written under "Achiki " and "Achi no Omi ", it also states the same information as the Kojiki. It also adds that he immigrated to Japan from Paekche with his son Tsuka no Omi and their people from seventeen districts, and founded the Yamatonoaya clan. |
| Shoku Nihongi | 797 | Written under "Achi no Omi ", it adds the claim that he is a descendant of Emperor Ling of Han. |
| Shinsen Shōjiroku | 815 | Written under "Achi no Ō ", it adds the claim that he is a descendant of Emperor Xian of Han. |
Regardless of the claims found in the sources, the truth surrounding Achi no Omi and the other prominent immigrants such as Wani and Yuzuki no Kimi remain skeptical with modern historians considering them as fictional individuals whose stories were added later to help create origin stories for clans with foreign backgrounds.
Name
Achi no Omi's name is often referenced differently depending on the source with four names in particular, "Achikishi", "Achiki", "Achi no Omi", and "Achi no Ō" being the main four candidates.| Names | Sources | Notes |
| Achikishi | Kojiki | "-Kishi" title is first introduced. Said to be the ancestor to Achishi. |
| Achiki Achi no Omi | Nihon Shoki | "Achiki" variant is first introduced. The "知" character is changed to "直", seen previously in his descendant's name in the Kojiki. "-Omi" title is first introduced. |
| Achi no Omi | Shoku Nihongi | - |
| Achi no Omi Achi no Ō | Shinsen Shōjiroku | "Achi no Omi" is written differently and is a name claimed by the Yamatonoaya clan. The "知" character is changed to "智". "-Ō" title is first introduced and is a name claimed by the Sakanoue clan. |
All of his names share the "Achi " pronunciation; however, depending on the character, some are confused as to whether these names were alluding to the same individual. In essence, the oldest name "Achikishi" is represented by the "阿知" characters in the Kojiki. This name is referenced again in the Nihon Shoki under "Achi no Omi" alongside another name, "Achiki" with the same pronunciation, but different spelling under "阿直". Though the premise of both names are similar, it is not specifically stated in the Nihon Shoki that these two are the same people, nor does it specify any instances that allude to the possibility of them being related. However, due to the Kojiki claiming that an individual of a similar name "Achishi " was the descendant of "Achikishi ", it can be deduced that "Achi" under "阿直" or "阿知" are in fact related. Furthermore, it is said that the Sakanoue clan's stables are related to the stables brought by Achiki from Paekche which supports the theory that Achiki and Achi no Omi were indeed the same individual.
Titles
The "-kishi " title in "Achikishi" is believed to be an allusion to the title "-gilji ", or "-kichi" in Old Korean, of Paekche when addressing their royalty, specifically to that of the king. In Paekche, the king was called "Geongilji " and it is believed that the title was given to Achikishi when depicting him of Paekche descent.The "-Omi " title in "Achi no Omi" is a variation of "Omi " a title under the Kabane system. However, the variation found in Achi no Omi's name is widely considered a version reserved more for Toraijins. It is also shared by fellow individuals from Korea known as Mantoku no Omi from Goguryeo,, as well as Tsurugamashi no Omi and his descendant, Sue no Omi from Paekche, adding credence to his Korean origin.
This sentiment is further examined in his alternate name, "Achi no Ō " or "King Achi" despite not referencing him of being royalty. It is believed that Achi no Omi and other invented clan founders were given the "King" title to elevate their importance in their respective clan's founding stories.
Legacy
Achi no Omi's son, Tsuka no Omi became father to three sons; Yamaki no Atai, Shido no Atai, and Isabuki no Atai, who all became ancestors to many powerful clans including the Yamatonoaya clan, Sakanoue clan, and many more. They all trace their lineage to Tsuka no Omi and thus, Achi no Omi.The Yamatonoaya clan, became the parent clan to many of its cadet branches including the famous Sakanoue clan. The said clan became famous for Sakanoue no Tamuramaro, who became a loyal servant to Emperor Kanmu where many of his children married into the imperial family.
It is also said that Achi no Omi was in fact the ancestor to the Ōtomo clan, another immigrant clan from Korea, according to the Sakanoue clan's genealogy. However, due to the conflicting claims made by the Sakanoue clan and the Ōtomo clan itself in regards to their respective founders, it is considered unlikely that Achi no Omi was the founder of the Ōtomo clan.