Tokyō is a system of supporting blocks and brackets supporting the eaves of a Japanese building, usually part of a Buddhist temple or Shinto shrine. The use of tokyō is made necessary by the extent to which the eaves protrude, a functionally essential element ofJapanese Buddhist architecture. The system has however always had also an important decorative function. Like most architectural elements in Japan, the system is Chinese in origin but has evolved since its arrival into several original forms. In its simplest configuration, the bracket system has a single projecting bracket and a single block, and is called hitotesaki. If the first bracket and block group support a second similar one, the whole system is called futatesaki, if three brackets are present it is called mitesaki, and so on until a maximum of six brackets as in the photo to the right. Each supporting block in most cases supports, besides the next bracket, a U-shaped supporting bracket set at 90° to the first. The Protection of Cultural Properties logo represents a tokyō, considered an element of Japanese architecture which stands for the continuity in time of cultural property protection.
Function and structure
The roof is the most visually impressive part of a Buddhist temple, often constituting half the size of the whole edifice. The slightly curved eaves extend far beyond the walls, covering verandas. Besides being determinant to the general look of the edifice, the oversize eaves give its interior a characteristic dimness, a factor which contributes to the temple's atmosphere. Finally, the eaves have a practical function in a country where rain is a common event, because they protect the building carrying by the rain as far as possible from its walls. The roof's weight must however be supported by complex bracket systems called tokyō. The further the eaves extend, the greater and more complex must the tokyō be. An added benefit of the tokyō system is its inherent elasticity, which lessens the impact of an earthquake by acting as a shock absorber. This bracketing system, being essential both structurally and esthetically, has been altered and refined many times since it was imported from China. It is made of a combination of weight bearing blocks and bracket arms. The bearing block, when set directly on a post, is called daito, or "large block". When it connects two brackets, it is instead called makito. Bearing blocks installed on top of corner posts are of necessity more complex and are called onito because of how difficult they are to make. In its simplest configuration, each tokyō includes a single outwardly-projecting bracket with a single supporting block, in which case the complex is called hitotesaki. The projecting bracket is just the tip of one of the roof's beams. If the first bracket and block group supports a second similar one, the whole complex is called. The tokyō may also have three or more such steps, up to six, extending laterally the support provided by the system. Wayō-, Zenshūyō- and Daibutsuyō-style tokyō all differ in details, the first being the simplest of the three. The Daibutsuyō style has for example a dish-shaped decoration called sarato under each block, while the Zen'yō rounds up in an arc the bracket's lower ends. Another Zenshūyō feature is the kobushibana or kibana, a nose-like decoration carved after the last protruding bracket. Some of these features can also be found in temples of non-Zen sects.
Notable types
Sumisonae
The sumisonae or sumitokyō are the brackets at the corner of a roof, having a particularly complex structure. The regular brackets between two sumisonae are called hirazonae or hiratokyou.
Futatesaki
Very common two-step bracketing system used in a variety of structures. See in the gallery for example the photo of a belltower.
Mitesaki
The three-step complex is the most common in Wayō-style structures. Its third step is usually supported by a so-called tail rafter, a cantilever set between the second and the third step.
Yotesaki
The four-step complex is used mainly in the top section of a tahōtō.
Mutesaki
The mutesaki tokyō is a six-step bracketing system whose most famous example can be seen at Tōdai-ji's Nandaimon. In that gate's case, it consists of just six projecting brackets with no brackets at right angles.
Kumo tokyō
The kumo tokyō is the Japanese equivalent of dieji in early Chinese architecture. It is a bracket system where the projecting bracket is shaped in a way thought to resemble a cloud. It is rare in extant temples, and its most important examples are found in Hōryū-ji's Kondō, five-storied pagoda and Chūmon. These bracket systems are believed to be a Japanese invention of the Asuka period, as there is no evidence they came from the Continent.
Sashihijiki
The sashihijiki is the Japanese equivalent of chagong in Chinese architecture. It is a bracket arm inserted directly into a pillar instead of resting onto a supporting block on top of a pillar, as was normal in the wayō style. Typical of the Daibutsuyō style, these brackets are clearly visible in the photo at the top of the article.
Tsumegumi
Tsumegumi are intercolumnar supporting brackets, usually futatesaki or mitesaki, installed one immediately after the other. The result is an extremely compact row of brackets. Tsumegumi are typical of the Zenshūyō style, which arrived to Japan with Zen Buddhism at the end of the 12th century.
