Arahabaki belief is a folk belief found in the Tohoku region. Many aspects of its origin are unknown and there is a theory that says it was a tradition that the people of eastern Japan, the Emishi (Ebisu, Ezo), who were considered 'Matsurowanu tami' (people who do not obey) preserved while they were being driven into the Tohoku region by the Yamato government/Imperial Court. There are various theories regarding the history and believability. There is a theory that says it is a type of Jomon god. It is also often tied up with ancient history, folklore, and false history.
Shrines dedicated to Arahabaki are common in the Tohoku region, but are also found south of the Kanto region. However, these shrines in many cases do not enshrine Arahabaki as the main god, but as a Monkyakujin (guest god). Monkyakujin means 'Maroudogami' (guest god) placed at the gate of the shrine and 'Maroudogami' is usually the local god whose land had been taken away by the later gods that feature in Japanese myths and is placed into the inferior guest god position. One case where Arahabaki is enshrined as a 'Maroudogami' for example is the 'Hikawa-jinja Shrine' in Omiya, Saitama Prefecture.
This sessha (auxiliary shrine [dedicated to a deity close-related to that of a main shrine]) is called the 'Monkyaku-jinja Shrine' but was originally called 'Arahabaki-jinja Shrine.'
Snake god theory
According to Yuko YOSHINO, the 'Haha' in 'Habaki' is an ancient word for snake. The word 'Hahaki' means 'snake tree' or 'dragon tree' and straight trees were originally the center of festivals and were portrayed as snakes.
At Ise Jingu Shine, a 'Hahaki-kami' is enshrined in a shrine that is positioned southwest from the inner shrine, in other words, the 'tatsumi' direction, and ceremonies are conducted on the 18th of June, September and December (Doyo days) at the 'hour of Mi' (around 10 am). Since 'Tatsu' means 'dragon' and 'Mi' means 'snake,' it is easy to imagine that it has a strong relation with snakes. It became 'Arahabaki-kami', in which "Hahaki-kami' is later added by the prefix for 'to appear' (ara).
Sae no kami theory
There is a Arahabaki-jinja Shrine located northwest of the remains of Taga-jo Castle in Miyagi Prefecture. Taga-jo Castle was the base built by the Nara and Heian period court to control the Emishi living in the Tohoku region. According to Kenichi TANIGAWA, it is said that Arahabaki was enshrined by the court to protect Taga-jo Castle from enemies. Obviously the court's enemy were the Emishi. In other words, he explains that Arahabaki had the characteristic of being a 'sae no kami' (god that prevents intrusion).
Additionally, according to Tanigawa, the traditional Emishi control strategy of the court was 'use the Emishi to control the Emishi,' and they used Arahabaki, which was originally an Emishi god, to protect Taga-jo Castle as a sae no kami and tried to ward off the Emishi.
Iron production god theory
The Arahabaki-jinja Shrine near Taga-jo Castle as mentioned above had shears as an offering and also lanterns made from cast iron. To the north of Taga-jo Castle were places that produced gold sand and iron sand.
Hikawa-jinja Shrine mentioned earlier for enshrining Arahabaki as a guest god is of the Izumo branch (transferred from Kitsuki-jinja Shrine located at Hi-kawa River of Izumo). Izumo is the place were iron production started in Japan. The monks at Hikawa-jinja Shrine are said to be a branch of the Mononobe clan, who were a clan of blacksmiths. Saitama Prefecture, where Hikawa-jinja Shrine is located, was the center of iron production industry in ancient times. However, there is also a theory that phonologically Hikawa came from 'Shikawa' and Hikawa came from 'Bikawa' and the two have no relation at all.
It is also worthwhile to note that the shrines in Hikawa-jinja Shrine group in Omiya (the three stars, Hikawa-jinja, Nakahikawa-jinja and Onnahikawa-jinja shrines, along with Tsuki-jinja Shrine, Munakata-jinja Shrine and Hisaizu-jinja Shrine in Koshigaya) are aligned in the shape of the constellation Orion, or Kamudo (god's gate) and if the Ara-kawa River that follow beside them is considered as the Milky Way, it seems to depict the skies. Furthermore, this Hikawa-jinja Shrine group is located on the other side of the Chichibu-jinja Shrine group (aligned in the shape of the Big Dipper = Amenotorifune, Ukefune) crossing the Hagihiyoshi-jinja Shrine in Tokigawa-cho, Hiki-gun. This suggests a strong relation with ancient Korean Dokyo because of the highly accurate measurement technology. Since Hikawa-jinja Shrine is an old establishment listed in the "the Engishiki" (an ancient book for codes and procedures on national rites and prayers) and the main god of Hikawa-jinja Shrine became Susanoo (in other words, the original main god Arahabaki became the guest god) only because of political reasons of the Edo bakufu (Japanese feudal government headed by a shogun), the story on the link between Izumo and Hikawa may be taken as part of the process of Emishi (including Toraijin [people from overseas, especially from China and Korea, who settled in early Japan and introduced Continental culture to the Japanese]) control by the Yamato Court.
According to Masakazu OMI, the gate guest god figure said to have transformed from Arahabaki often has only one eye. Having one eye is said to be a characteristic of the god of iron production.
Additionally, Omi explains that 'Ara' is an ancient word for iron and Shugendo (Japanese mountain asceticism-shamanism incorporating Shinto and Buddhist concepts), which was actually involved in iron production using mountain iron sand and collecting other minerals, incorporated Arahabaki beliefs, and 'Habaki' is related to the 'Habaki' (shin guard) which Yamabushi (a mountain priest) considers holy and therefore Arahabaki eventually transformed into a 'god of feet,' considering 'your legs get better if you worship at the shrine.'
Tsunetada MAYUMI explains that the aforementioned 'sae no kami' originally meant 'Sahi (iron) no kami' and here 'sae no kami' and the god of iron production is linked.
Relation with Shitenno-ji Temple
It has been suggested that Shitenno-ji Temple in Osaka City, which was the first large temple built in Japan by Prince Shotoku when he battled and defeated MONONOBE no Moriya over accepting Buddhism, has a relationship with Arahabaki and Jomon culture.
The original place name of Shitennoji was presumably 'Arabaki' and it is said to have been the land of the Mononobe clan who were considered as the branch of Jomon culture.
Iwafune-jinja Shrine (place where Nigihaya no mikoto descended to earth) is said to have been located at the north side of the present Shitenno-ji Temple. Considering the fact that the Mononobe clan consider their founding father as Nigihaya no mikoto, the land where Shitenno-ji Temple is located seems to be originally the holy place where the Mononobe clan started.