1. Enshrined Gods
1) Main gods: Amatsuhikoho-no-ninigi-no-mikoto and Takemikazuchi-no-mikoto
2) Other gods: Amaterasuo-o-mikami, Toyouke-no-o-kami, Toyotamahime-no-kami, Sukunahikona-no-kami, O-yamakui-no-kami, O-namochi-no-kami, and Sainokamimihashira-no-kami
2. Dates for the Annual Festival: July 16 (the eve of July 15th)
3. Other Regular Festivals: New Year’s festival on January 1, Sedo festival on January 3, Namahage-Sedo festival on the second Friday of February and on the following Saturday and Sunday, Niinamesai on November 18, Hatahata festival in mid-November, the last day of the year festival on December 31, and the monthly festival on the 16th of every month.
According to the records of the shrine, its foundation goes back to the time of the reign of Emperor Keiko. Takenouchi-no-Sukue was sent to the northern provinces for inspection and climbed Mt. Wakiide in Oga. Here he enshrined two gods, Ninigi-no-mikoto (or Amatsuhikoho-no-ninigi-no-mikoto) and Takemikazuchi-no-mikoto, in wish for the completion of his mission, the safety of his soldiers, and the security of the nation.
During the Heian era (794–1185), Buddhism expanded its influence to the Oga peninsula. During the Jogan period (859–877), Jikaku-Daishi (or Ennin, 793–864, one of the highest priests of the Tendai School of Japanese Buddhism) divided Mt. Wakiide into two areas, and named the northern part Shinzan (for Shinto) and the southern part Honzan (for Buddhism).
The Shugen sect (Japanese asceticism-shermanism practiced on mountains with concepts from Shinto and Buddhism) developed in the area. In the 14th century, the priests of the Tendai Buddhist sect assimilated the gods of the Sinzan shrine with Sekizan Myojin, the tutelary god of Enryakuji Temple on Mt. Hiei (the headquarters of the Tendai sect), while Kobohji Temple that was under the control of the Shinzan Shrine converted from the Tendai sect to the Shingon sect. The ruler of the area changed through the Heian era from the Abe family to the Kiyohara family, and then to the Fujiwara family, but the protection for Shinzan and Honzan remained unchanged, which prospered as a center of the Shugen sect.
During the Edo era, since the Shinzan shrine was chosen as one of the twelve shrines of the Kubota Domain and thus designated as a place of worship for Lord Satake, it received many donations and afforded many buildings and towers on its premises.
After the Meiji government issued the order of separation between shrines and temples in 1868, the entire area was restored as a Shinto sanctuary and the name was changed from Akagami shrine to Shinzan shrine. In 1881, it was designated as a prefectural shrine and has maintained its status as a holy precinct ever since.
In September 1991 the shrine was seriously damaged by old cedar trees that were blown down by a typhoon, but seven years of reconstruction work fully re-established it.
The main shrine is as ever at the top of Mt. Shinzan and receives reverence as deities of the security of the nation, good harvests for all crops, maritime safety, and good fortune.
5. Sedo Festival
This festival is a unique religious event that prays for the village’s safety, good harvest, good catches of fish, and the removal of epidemics. In the evening of January 3, a giant rice cake roasted over a sacred fire is offered to the gods of the shrine.
Namahage are said to be the incarnation of shinki (messengers of gods), and the Namahage festival has been practiced since the Choji period (1104–1106).
Every year on the second Friday of February and the following Saturday and Sunday, the Namahage Sedo festival is held here. The rice cake offered to the shinki is shared with the parishioners and visitors as a charm against misfortune. The religious service is carried out at night during the coldest season, and it is widely known as one of the five biggest snow festivals in the Tohoku region.