Achi no omi

Achi no omi (阿知使主) also known as Achiki (阿直岐) or Achikishi (阿知吉師), was the legendary founder of the "Yamatonoaya clan (東漢氏)" who settled in Japan with his son Tsuga no omi. He is considered one of the three most influential Toraijins alongside Yuzuki no Kimi and Wani during the Kofun period.

Origin
He is first mentioned in the Nihon Shoki when discussing about his arrival in Japan.

However, due to conflicting details across several sources that claim different origins of Achi no omi, several theories have been proposed by modern historians.

According to Shoku Nihongi (797), it is said that he was the great-grandson of Emperor Ling of Han (other sources said he was still a descendant of Emperor Xian of Han being either his grandson or great grandson) which is the reason why his clan was named "東漢" meaning "Eastern Han" in Chinese characters. On the contrary, older documents such as the Nihon Shoki (720) and Kojiki (711) state that Achi no omi and his clan, the Yamatonoaya clan had originated from the kingdom of Baekje.

Japanese scholars have indicated that Yamatonoaya clan and other "Aya (漢)" clans were all related and that they were generally classified under the same ethnic group. These mainly included: the "Aya clan (漢氏)", the "Yamatonoaya clan (東漢氏/倭漢氏)" and the "Kawachinoaya clan (西漢氏/河内漢氏)". It is said that Yamatonoaya clan, Aya and Kawachinoaya, though not from the same founder, were ethnically related, most likely all immigrating from Baekje.

"百濟王遣阿直岐，貢良馬二匹. 即養於輕阪上厩. 因以阿直岐令掌飼. 阿直岐亦能讀經典. 及太子菟道稚郎子師焉. 於是天皇問阿直岐曰，如勝汝博士亦有耶. 對曰，有王仁者. 是秀也. 時遣上毛野君祖荒田別・巫別於百濟，仍徴王仁也. The King of Baekje sent Achiki (Achi no omi) to deliver two horses. He was stationed at a stable in Karu where he took care of the horses. He was a master of reading scriptures and was placed as the mentor to Ujinowakiiratsuko. One day, the Emperor of Japan asked him "is there someone more talented than yourself?" and he replied, "a great scholar named Wani". The emperor dispatched his men to bring Wani from Baekje."

"Kawachinoaya (西漢氏)" in particular, is thought to be related with the Yamatonoaya clan. The clan was one of the clans first founded by the scholar Wani (alongside clans such as "Kawachinofumi clan (西文氏)") who arrived in Japan from the kingdom of Baekje who helped spread the use of the Chinese Writing system in Japan. According to Japanese scholars, Wani and Achi no omi founded Kawachinoaya and Yamatonoaya clan respectively, both being of Baekje origin and influential ethnic Koreans in Japan at the time. They shared the same character "Aya" but separated one another with the use of cardinal directions ("Kawachi/西" meaning West and "Yamato/東" meaning East) as Wani's Kawachinoaya clan resided in "Furuichikoori (河内国古市郡)", (present day Furuichigun (古市郡) [ ja] in Osaka) located in the west of Japan, while Achi no omi and his Yamatonoaya clan resided in the Yamato Kingdom found in the east. Some also theorized that he and his clan originated from the Gaya confederacy, specifically from the kingdom of "Aya (安邪国)" (old name for Ara Gaya) where the placename became the etymology of the Aya clans. According to this theory, the immigrants brought many Baekje technologies from Aya and were considered as close kin to the people of Baekje. Some nationalist historians used this to support the claims over the Mimana controversy stating that Mimana (Gaya) was in fact Japanese due to the relations between the kingdom of Aya and the Aya clans of Japan. Despite the lukewarm reception in Korea, evidence alludes to the possibilities of Japanese speakers in the region.

Much like the Hata clan, modern Japanese historians state that historical and archeological evidence allude to Korean origins (specifically of Baekje or Gaya), therefore in recent times, Achi no omi and his clan are perceived as Korean in Japan.