Izumo Taisha Grand Shrine is a Shinto shrine. Shinto is indigenous and one of the two major religions of Japan (The other is Buddhism, which came to Japan around the 6th Century). Shinto is polytheistic and it is believed that there are multitudinous gods in Japan.
Among them is O-kuninushi-no-okami, who is enshrined in the main hall of Izumo Taisha. According to mythology, the god created all things under the heavens. He is commonly known as the god of En-musubi (match-making), the creator and arranger of relationships. These relationships are not only those that bind men and women together in marriage, but also those that bind friends, good business partners, and all things together.
The main hall of Izumo Taisha has been described as a building of magnificence since ancient times. In a book compiled in the 10th Century, it was depicted as the largest building that existed at the time. The Great Buddha Hall of Todaiji in present-day Nara Prefecture was the second largest. The current main hall structure is the largest of its kind in Japan.
"Sengu" literally means to move the go-shintai （the sacred representation of the enshrined god) from the original sanctuary to a temporary shrine, while construction of a new shrine building or repair work on the shrine building is conducted. There are various theories about the purpose of the Sengu. Below are some of them:
- To maintain the wooden structures,
- To pass on traditional artisans' techniques,
- To keep the shrine building immaculate and clean (As a result, the power and vitality of the god of the shrine is thought to be renewed).
In April 2008, Kari-den senza-sai, a ritual to transfer the sacred representation of the enshrined god to the temporary main hall, was held. After the repair work, which took about five years to be completed, Hon-den senza-sai, a ritual to transfer back the god to the main hall, was conducted in May of 2013.
In addition to the main hall, a lot of shrines of various sizes which enshrine the gods, who are closely connected to O-kuninishi-no-okami, can be found surrounding the Izumo Taisha. The repair work on the shrines and other structures will be completed in 2016.