Understanding true “sustainability” as demonstrated by Ise Jingu’s 2000-year-old traditions

What is Shikinen Sengu?

Shikinen Sengu is a sacred ceremony that involves remaking the shrine buildings at Ise Jingu, along with all sacred furnishings and apparel, and welcoming the deities to the new buildings once in every 20 years. Continuing this tradition is what has allowed Jingu to always maintain a fresh appearance throughout the centuries, a concept known in Japanese as “tokowaka.”

The sacred Shikinen Sengu ceremony was first held about 1,300 years ago. Since then, the ceremony has been held regularly until the present day; the latest was the 62nd ceremony, held in 2013.

The next Shikinen Sengu will take place in 2033, with various related rituals and ceremonies commencing in 2025.

History Revealed Through Architecture

During Shikinen Sengu, about 170 buildings are rebuilt; these not only encompass the main sanctuaries of the Naiku and Geku, but also 14 affiliated jinja (shrines) and torii gates. The shrine buildings are built in the architectural style known as Yuiitsu shinmei-zukuri, a simple and antiquated style originating in granaries from the Yayoi period (a period of Japanese history from about 2,300 to 1,700 years ago), but in a variation exclusively used at Ise Jingu. Structures built in this style include posts set in the ground called hottate bashira, which add a high level of earthquake resistance. Through Shikinen Sengu, the ancient construction techniques of Yuiitsu shinmei-zukuri are being passed on as well.

Moreover, timber left over from dismantling the old buildings is reused instead of being thrown away. For example, wood materials have been given new life as torii gates used at historical sites within Mie Prefecture, including Ujibashi Bridge in the Naiku inner sanctuary.

The Future of the Forest at Jingu

Upstream of the Isuzugawa River that flows around the edge of Naiku is a vast forest known as Kyuikirin (“shrine precinct forest”). The wood used for building the shrine buildings at Ise Jingu used to be supplied by the hinoki cypress trees that once grew in this forest; these days, however, it is supplied by trees from the Kiso region of Nagano Prefecture. Nevertheless, beginning in the Taisho era (1912–1926), efforts have been made to plant hinoki cypress at Kyuikirin as a way of once again creating a source of timber at the sacred forest. While 2023 marks exactly a century since these efforts began, another one hundred years of growth is required to make sure that the trees can supply enough timber.

The aim of this afforestation is not only to use the timber for building the shrine buildings at Jingu, but also to create a sturdy forest that will protect the region from natural disasters. Kyuikirin also plays a role in protecting local water sources and landscapes, along with people’s lives and livelihoods.

Pride of the Shinryomin: Okihiki Festival

Photo provided by Jingushicho (Jingu Administration Office)

Once the hinoki timber used for constructing the shrine buildings at Ise Jingu arrives in Ise, it is transported to the shrine grounds as part of Okihiki, a festival in which local residents take part.

Okihiki is one of the few ceremonies related to Shikinen Sengu that gives Ise residents the chance to participate. Once every two decades, the most exciting folk event in Ise sweeps across the city.

The term shinryomin once referred to people who lived and worked within the Jingu shrine precinct; these days, it is used for those who reside in Ise City. Originally positioned as a voluntary duty for shinryomin, the modern-day Okihiki Festival has become a grand tradition in Ise and a source of pride for shinryomin.

Why is Shikinen Sengu Held Every 20 Years?

Various theories exist as to why Shikinen Sengu is held every 20 years. One theory is that it is connected to the time required for sufficiently passing down the skills of shrine carpenters, which is considered to be 20 years. Another theory is that it is linked to the storage period of rice used to fund the shrine rebuilding, which was decreed to be 20 years by law. Others believe that it originates from the day on which the start of winter solstice (touji) coincides with the new moon. Known as “Sakutan Touji,” the event occurs every 19 years and seven months. It is thought to signify taking the opportunity to return to the starting point and contemplate new beginnings.

1,500 Rituals at Ise Jingu

Photo provided by Jingushicho (Jingu Administration Office)

In addition to Shikinen Sengu, about 1,500 other rituals are held at Ise Jingu each year. These are referred to as annual rituals. Among them, Kanname-sai in October is considered to be of particular importance, with various other rituals held throughout the year thought to be tied to this one ritual.
According to Japanese mythology, Japan’s staple food, rice, was bestowed to the nation by the goddess Amaterasu-Omikami.
Since daily life and activity centered on agriculture, the ritual is held to give thanks for the autumn harvest and pray for bountiful harvests, the security of Japan, and peace among people.

Higoto-asa-yu-omike-sai

Higoto-asa-yu-omike-sai is a Jingu ritual held twice daily in the morning and evening.

This ritual has taken place for 1,500 years, ever since the Geku outer sanctuary was erected. It involves offering meals morning and night to the deities of the Naiku, Geku, and affiliated jinja, along with praying for the security of Japan and peace among people, and offering thanks.

The offerings include a set menu of steamed rice, dried bonito, fish, seaweed, vegetables, fruit, salt, water, and sacred rice wine. Following preparation by priests, the sacred meal is purified with salt, then carried to the Mikeden.

At Jingu, the Imperial estates such as Jingu Shinden and Jingu Misono are managed to be self-sufficient in producing these offerings.

At Geku, you can spot the priests crossing the approach to the Mikeden as they carry out the Higoto-asa-yu-omike-sai ritual.

April to September: Before 8 a.m. and just after 3 p.m.
October to March: Before 9 a.m. and just after 2 p.m.
*The actual times may vary slightly

At Ise Jingu, traditions spanning two millennia are carried into the present through Shikinen Sengu and daily rituals. These sustainable activities provide an example of modern sustainability.