From Protocol of the Gods: A Study of the Kasuga Cult in Japanese History by Allan G. Grapard
“Ame-No-Koyane-No-Mikoto and the Mirror
The third kami enshrined at Kasuga is Ame-no-koyane-no-mikoto, who is regarded as the ancestral kami of the Nakatomi sacerdotal lineage and consequently of the Fujiwara house, which emerged from that lineage in 669. There is no doubt about the identity of that kami, for its role is clearly defined in the Kojiki and the Nihon shoki, where it appears in what may be the most famous scene in Japanese mythology….” — Protocol of the Gods: A Study of the Kasuga Cult in Japanese History by Allan G. Grapard
[Ame no koyane no mikoto] (Kojiki)
Called an ancestor of the Nakatomi clan, this kami is described in various traditions as the child of Kogotomusuhi (Nihongi) or Kamimusuhi no kami (Kogo shūi), or a third generation descendant of Tsuhayamusuhi no mikoto (Shinsen shōjiroku). At the time of Amaterasu’s retreat into the rock cave of heaven, Koyane performed incantations by reciting norito litany, and at the time of the Descent of the Heavenly Grandchild (tenson kōrin), he acted as one of the “chiefs of the five clans” who accompanied Ninigi. According to Nihongi, he was “the first in charge of divine affairs, for which reason he was made to serve by performing the Greater Divination.” Within the imperial palace, he was known as the one who had been commanded by Amaterasu ōmikami to guard the divine mirror, with the result that he held the status of “Imperial Aide” (Tennō hohitsu no kami) with responsibility for presiding over divine affairs within the palace. Based on his status as ancestral kami (sojin) to the Fujiwara (Nakatomi) clan, he is worshiped at the clan’s shrines, including the Hiraoka Jinja and Kasuga Taisha. –Mori Mizue Encyclopedia of Shinto
Do the Koya have possible origins from the NE region of the Indian subcontinent?
“Koyane” means born in Koya, and so Ame-no-koyane-no-mikoto could mean the Heavenly born-of-Koya king.
Koya-san (or Mount Koya) is an important sacred center for mountain pilgrimages and the practice of ascetism in Japan. According to Koya-san tradition,
“Mount Koya (Koya-san) was founded in 816 by imperial decree for Kobo Daishi [Kukai] (774-835), who had returned from the T’ang dynasty capital of Ch’ang-an imbued with Chinese civilization and Indian Mantrayana Buddhism. To believers Kukai sits inside a locked Koya-san temple in a meditative state that may be compared to the Buddha’s Parinirvana. Koya-san remains the headquarters of Kukai’s Shingon Buddhism, with Kongobuji the head temple of the sect. Today Koya-san remains a mountaintop monastic town in Wakayama prefecture near southern Nara prefecture.” — Encyclopedia of Monasticism (via Steve McCarty’s article on Mt Koya, Japan)
It is not inconceivable that a chief of the tribe of the Koya-descended peoples may have been one of the five clans to follow Ninigi, acting as his chief liturgical leader, and that Kobo Daishi may have been of or supported by an entourage of that lineage or that he chose to found Mt. Koya in 816 because of the importance of the Koya-descended community there… See also Maitreya the Future Buddha, by Alan Sponberg, Helen Hardacre on Kukai choosing Mt Koya as his Matrix Realm and believing it would be the place where Maitreya would descend to, and on the strong associations with caves.
The Dravidian-speaking Koya live in the forests, plains, and valleys on both sides of the Godavari River, which lies in the central Indian state of Andhra Pradesh. Many also live in the states of Madhya Pradesh and Orissa, mostly known to live in the mountainous ranges and said to be . The Koya are said to have migrated to central India from their original home in Bastar, northern India. Their main deity still resides in a cave in the Bastar region. Other major deities of the Koya are Lord Krishna and Lord Bhima (whose emblem is the mace). The Koya claim their origin from the pandavas of the epic Mahabharata, especially the lord Bhima. When the pandava brothers were in exile, Bhima went hunting in the jungle and met a wild woman of the woods and subsequently got married. The fruit of the union was the Koya people. There are other legends connected with their origin.
On Mt. Koya, many Light related Deities and Bodhisatvas, and rituals such as Light Offerings play an important part at the temples, for example the “festival of ten thousand lights” (mandoo-e 万灯会) at the Temple Toodai-ji on August 15, during the O-Bon Festival period.
In India: While Divali or Deepavali, the Festival of Lights is usually an occasion of great importance celebrated by mainly Jains, and other northern Indians, Divali is also one of the seven most important festivals in Andyra Pradesh, but celebrated by Koyas with a difference … as the day that commemorates the death of Narakasura at the hands of Lord Sri Krishna. Narakasura, a malevolent demon, was said to have tortured common people and that the people prayed to lord Krishna to defeat him. The people then celebrated Narakasura’s defeat with sparkles, lights and crackers. Some areas host local stage story telling called Hari Katha. Some areas may put a huge Narakasura dummy made with fireworks. This will be burst by a person dressed as Lord Krishna or, more accurately, a costume of Satyabhama, the consort of Lord Krishna, who is believed to have killed the demon Narakasura. Tradition has it that Andhraites make and gift sweets during Diwali. Other traditional customs include buying new clothes for this festival (as well as a new home or vehicles).
The Koya language, also called Kaya, Koi, Koi Gondi, Koyato, Raj Koya among other names, is closely related to Gondi and has been strongly influenced by Telugu, the tongue of the neighboring Hindu population. Most Koya speak either Gondi or Telugu, in addition to Koya.
Many practices on Mt Koya or Koya-san appear to be of Northern Indian origin or influenced, such as the goma fire ritual. However, the trails have for the most part been erased by time and local historical events, and we only have circumstantial evidence that such tribes out of India may have descended upon Japan “with Ninigi” a very long time ago.
People of India: Maharashtra, Part 2 ed. B. V. Bhanu p. 1162