The Torii in Japanese culture is a very important part of Japanese shrines, and its significance as a spiritual symbol far exceeds its actual significance. The act of "through Torii" is also unusual because of the spiritual significance of Torii itself. The Torii is an accessory building of Japanese shrines and is regarded as a portal in the Shinto system. The earliest history of Torii can be traced back to the Nara era, when the original Torii appeared as a door in the shrine building. The original Torii was composed of wood and rope, and it evolved into its current common form in the 8th century AD.

The color of the Torii is usually the color of the material body, and the most common red Torii today belongs to the Inaga Shrine system, where the ancient Japanese believed that vermilion could bring warmth and Yang in spring, thus promoting agricultural production. Because of the significance of the Torii as a boundary marker, it is the act of "going through Torii" that is important to its use. Although Torii does not divide space in the physical sense, its spiritual meaning also represents the entry of one space into another different space. If this action is changed, the meaning of Torii will also change. Therefore, behind every Torii there is an artificially defined invisible space (in the Shinto system this is called the boundary); it is this mysterious space that becomes re-visualized through casting nested spaces.