Sengū

Sengū (遷宮) is the Japanese term for the transfer of a shintai to a Shintō shrine. When the honden, the main hall of a Shintō shrine, is repaired or rebuilt, the shintai must be moved. Ceremonies to mark this occasion are also called Sengū. During sengū, the shrine's main buildings and sacred items are rebuilt and renewed. The main sanctuary and other structures are constructed anew. All sacred garments and treasures are also replaced.

is the term used for ceremonies at Ise-jingū (Mie Prefecture) and Sumiyoshi taisha in Ōsaka in which the main hall is identically and completely rebuilt at fixed intervals (shikinen) on one of two adjacent sites. At the shrine renewal, the shintai is then transferred to the new honden at a solemn ceremony (sengū) and the old building is burned down. One of the new sacred mirrors is offered at this time by the Tennō himself. It is said that this ceremony is related to the Shikinensai, the commemoration of the anniversary of the death of a historical emperor.

The sengū ritual began in the 7th century. It was initiated by Emperor Tenmu during a time of civil unrest. The first sengū ceremony took place in 690 for the Inner Shrine and in 692 for the Outer Shrine. This tradition has continued for over 1,300 years.

The process of rebuilding the shrine is governed by specific laws. These were first recorded in the Engi period (901–922). The laws state that every twenty years, the main sanctuary and other buildings must be renewed. All materials used must be new. The sacred treasures are then moved to the new buildings.

The shrine’s design is simple yet distinctive. It uses materials like cypress wood, miscanthus reeds, and metal hardware. The main sanctuary has a special central post. The simple design means the buildings decay over time, requiring periodic renewal.

The renewal process is a large-scale project. It takes eight years to complete. It requires thousands of pieces of timber, reeds, and many carpenters. Over sixty structures are rebuilt. These include sanctuaries, treasure houses, and gates. New sacred garments and treasures are also made.

There are various ceremonies during the construction. These include rituals for cutting and transporting wood and building the shrine. The main ritual, Sengyo, happens in October. It marks the transfer of the deity to the new shrine. During this time, the emperor performs a distant worship ritual.

The sengū ritual has evolved over time. In the past, the imperial court managed the rebuilding. Later, a rice tax was used to fund the construction. After a break in the tradition due to warfare, the ritual resumed in the 16th century. In the modern era, the Japanese government oversees the process.

In addition to the shrines at Ise and Sumiyoshi, such ceremonies were once held at other shrines, including the Katori-jingū, the Kashima-jingū, the Usa-jingū, the Kasuga-taisha, and the Suwa-taisha (the Onbashira-sai).