Also sasuzuka sasuzaoshiki 扠首束扠首竿式, *sasuzao 扠首竿, *sasu 扠首.
Two diagonal struts, sasuzao, set in such a way that their tops butt against each other with equal force and are secured by a mortise and tenon. In simplest form one inokosasu supports the ridge *mune 棟 at each end. However, with the introduction of Buddhism in the mid-6th century, temple architecture, and later Shinto shrine buildings, a center strut *sasuzuka 扠首束, to give further support. This simple framework is placed upon each transverse beam creating one type of roof structure. In turn, each is capped with either a large, single bearing block *daito 大斗, with a boat-shaped bracket arm inserted, or with a bracket arm that has three smaller bearing blocks *mitsudo tokyō 三斗斗きょう to carry the ridgepole *munagi 棟木. Since these structural members appear in the gable pediment *tsuma 妻, they create a decorative pattern *tsumakazari 妻飾 for buildings with gable roofs *kirizuma-zukuri 切妻造 or with hip-and-gable roofs *irimoya-zukuri 入母造.
Examples: Tōdaiji *Hokkedō 東大寺法華堂 (8th century) in Nara, above the ceiling in the oldest end, an inokosasu is used with diagonal braces without a central strut. At Hōryūji *Kondō 法隆寺金堂 (late 7th century) in Nara, the inokosasu has diagonal braces with central struts to carry the bracket complexes that support the ridge.
Occasionally the diagonal braces are somewhat curved. Those, used on the exposed roof of the Murōji Kondō 室生寺金堂 (8th century) in Nara, were curved. The use of inokosasu construction was not confined to temples and shrines but also employed in the roof structures of dwellings.
