In Shinto legends about Susanoo, notably in the Kojiki: An Account of Ancient Matters, Ashinazuchi was the father of Kushi Inada Hime (or Kushinada Hime), a young woman of the Izumo region who was to be sacrificed to an eight-headed monster, Yamata no Orochi, who haunted the region. She was saved from death by Susanoo, who killed the dragon and then married her. Her mother named her Tenazuchi (other versions have Tenazuchi as Ashinazuchi’s wife). As for Ashinazuchi, he was said to be the son of Oyamazumi no Kami of Izumo.
Source: Japan Encyclopedia by Louis Frederic
We draw an inference here that the royal lineages from Izumo, downstream of Ashinazuchi, father of Kushi Inada Hime, were possibly of the Hun / Hunnu / Xiongnu (proto-Turko-Mongol or proto-Turkic) Ashina royal clans from the continent:
“The name Ashina first appeared in the Chinese records of the 6th century, and prior to that no other sources had related their history at all.
About 460 they were subjugated by the Rouran, who ousted them from Xinjiang into the Altay Mountains, where the Ashina gradually emerged as the leaders of the early Turkic confederation, known as the Goturks.
The Orkhon Valley was the centre of the Ashina power.
After the collapse of the Gokurk empire under pressure from the resurgent Uyghurs, branches of the Ashina clan moved westward to Europe, where they became the kaghans of the Khazars and possibly other nomadic peoples with Turkic roots.
According to Marquart, the Ashina clan constituted a noble caste throughout the steppes. Similarly, the Tatar historian Zeki Validi Togan described them as a “desert aristocracy” that provided rulers for a number of Eurasian nomadic empires.
Accounts of the Goturk and Khazar khaganates suggest that the Ashina clan was accorded sacred, perhaps quasi-divine status in the shamanic religion practiced by the steppe nomads of the first millennium CE.”
In Japan, the Ashina have been recorded in “Royals of Japan” as daimyo families of Miura, and by them, of the Taira. Source: Ashina — Famille de daimyo descendant des Miura et par eux des Taira. Puissante en Mutsu aux 15 e et 16e siècles. / Tr. Family of daimyos descendants of Miura and Taira. Stronghold in Mutsu during the 15th and 16th centuries. — Source: “NOBILIAIRE DU JAPON” (or Royals of Japan) by Jacques Edmond Joseph Papinot et al.
While in Japan, the traceable ethonym Ashinazuchi – zuchi means “elder” genetic lineage; on the continent, zuchi is a homonym for the common Zuchi and Jochi (Mongolian: Зүчи, Züchi, Kazakh: Жошы, Chinese: 术赤, Zhoshy, Crimean Tatar: Cuçi; also spelled Jöchi and Juchi) . Jochi (c. 1181 – February 1227), for example, was the name of historically known figure, eldest son of Genghis Khan. The Ashina, Xiongnu, Mongol and Turkic lineages (as well as Japanese lineages) have common clan histories or genealogies and mythical identities, involving elements of an ancestral hero who according to tradition is supposed to have been subjected to infant exposure and then having been rescued by a wolf, is then regarded as having been descended from “wolves“. In addition, the genealogical tales commonly include as well as the appearance of the same mythical archetype of a founder-ancestor elderly couple (along with divine status, regalia, quarreling sibling motifs) that is found in the Kojiki and Nihongi texts and other mythical narratives — these common threads in clan genealogies and hero stories, strongly suggests to us a shared tradition between Mongol and Koreanic populations and ultimately, Japan’s – see “Cultural heroes and agricultural gods in elderly garb“, (motifs possibly traceable even further to either a remoter West Asian or West Eurasian origin or that constitute Hunnic motifs to have diffused to the west to form part of the European wolf and slaying-the-dragon traditions).
In Victor Mair’s “Contact and exchange in the Ancient World“, p. 141 he notes the historical account given by the Chinese Sui-shu (Book of Sui) where “the Turks are portrayed as stemming from “mixed-Hu barbarians” from P’ingLiang in Kansu[Gansu] who had the clan name A-shih-na” [Ashina in Soghdians; Axsina or Axsena to the Iranians; Axsainnaka in Old Persian; Arsila to the Byzantine-Turks; Axsaena in Avestan; Assena to the Khotanese-Saka; Asna for “blue” in Tocharian which ties in with Gokturk which means Blue Turk, as inscribed in the Kul Tegin tomb] We are told that after the Northern Wei Emperor Tai Wu-Ti ended the Xiongnu statelet of Chu-Ch’u in Gansu “in 439 the A-shih-na with five hundred families shifted to the Jou-jan lands, submitted to them and settled there as ironworkers.” Mair underlines that the A-shih-na acquired their metallurgical skills in the East Turkistan and Gansu areas associated with East Iranian and Tocharian populations. The Qarluq ruling house was also noted to be of Ashina origin.
On the DNA front
The genetic marker/Y-DNA haplogroup Q-M378 has been located in the tomb of the Yeniseian language speaking Xiongnu/Hunnu aristocracy at the Heigouliang cemetery (Xiongnu king summer camp)- the Black Gouliang barrow to the east of the Barkol Basin at the ruins of Hami (Kumul) in North Xinjiang (at the Mongolian border) from 2nd-1st century BCE. This same genetic marker/Y-DNA haplogroup Q-M378 has been detected among contemporary Uyghurs of Xinjiang (2010, 2014) [available Uyghur Q-M378 haplotypes shows striking similarity to those of Ashkenazi Q-M378 suggesting that at least part of Uyghur Q-M378 actually are L245] and more importantly, haplogroup Q-M378 has been also located throughout Mongolia and in Japan (source: 2007 Royal Ashina Khazaria DNA project).
In Japan, the Ashina clan (using the kanji Kan-on characters, 蘆名氏, “芦名” and “葦名”) is mostly spread out over the Kanagawa, in the Kanto region’s, including Kamakura. The name came from the area called Ashina in the city of Yokosuka in Kanagawa Prefecture. The clan claims descent from Taira clan through the Miura clan a clan prominent during the Sengoku period.
Further sources on the Ashina clan: