ise grand shrine has continued the tradition of rebuilding every 20 years, into an adjacent land with exactly the same specifications since the time of empress jitō in the end of the 7th century. similarly, the tradition of replacing old sacred treasures with new ones of exactly the same specifications has continued. this tradition is based on the idea of in shinto, that new objects have stronger divine power. there are 1576 sacred treasures that are renewed every 20 years, and sugari no ontachi is the most important sacred treasure along with in the sword category.