Halo found on Buddhist images, representing light said to be emitted by the Buddha *gokō 後光. In sculpture, a wooden or metal kōhai was attached to the back of the figure, sometimes decorated in openwork *sukashibori 透彫. Kōhai were used in Japan from the Asuka period, usually made of bronze or gilt bronze, and were named according to their shape and design. One of the earliest examples is the halo on the Shaka Sanzonzō 釈迦三尊像 (623) in Hōryūji 法隆寺, which is known as ikkō sanzon kōhai 一光三尊光背 (the single-light triad halo, see *ikkō sanzon 一光三尊), because all three figures of the triad are enclosed in a single halo. The halo surrounds the figures completely *kyoshinkō 挙身光 and has a pointed top, giving it the name *funagata kōhai 舟形光背 (the boat-shaped halo). Individual standing figures of the same period had round halos *enkō 円光 as on the Four Heavenly Kings, Shitennō 四天王 in Hōryūji *Kondō 法隆寺金堂, or jewel-shaped halos *hōjugata kōhai 宝珠形光背, like that of the Kudara Kannonzō 百済観音像 in Hōryūji Daihōzōden 法隆寺大宝蔵殿. In the Tenpyō period, the double-round halo *nijū-enkō 二重円光 became popular. A round head-nimbus *zukō 頭光 is attached to a round body-nimbus *shinkō 身光, as on the Miroku Bosatsuzō 弥勒菩薩像 in Hōryūji Daihōzōden 法隆寺大宝蔵殿. Halos decorated with Chinese foliage design *karakusamon 唐草文 and a thousand miniature buddhas senbutsu kōhai 千仏光背 were also produced in the Tenpyō period. A good example is *Rushanabutsu 盧舎那仏 (779) in Tōshōdaiji 唐招堤寺, Nara. In the Heian period halos with a decorated base *kōkyaku 光脚 became popular. *Ten 天 and *Myōō 明王 figures had halos with flame designs *kaen kōhai 火焔光背. The earliest examples of wooden halos *itakōhai 板光背 date from the late 9th century, and these were often painted with flames, karakusamon, and small manifestations of buddha *kebutsu 化仏, as on the Shaka Ryūzō 釈迦立像 in Murōji 室生寺, Nara. In the 12th century nijū enkō were surrounded by a large outer boat-shaped halo of openwork flying apsaras figures *hiten kōhai 飛天光背. The model for this style was the Amida Nyoraizō 阿弥陀如来像 (1053) by Jōchō 定朝 in Byōdōin *Hōōdō 平等院鳳凰堂, Kyoto. Other styles characteristic of the late Heian period were the single free-standing ring *rinkō 輪光 like that of the *Kichijōten 吉祥天 in Jōruriji 浄瑠璃寺, Kyoto; a halo with radiating spokes like a wheel, hōshagata kōhai 放射形光背, seen on the Amida Nyoraizō in Kanzeonji 観世音寺, Fukuoka Prefecture; and the *mibu kōhai 壬生光背 named after the Jizō Bosatsuzō 地蔵菩薩像 in Mibudera 壬生寺, Kyoto (now lost). In the Kamakura period, various designs of kōhai with openwork decoration continued to be produced, as well as halos decorated with small figures representing the followers of Buddha *kenzoku 眷属, as on the central Senju Kannonzō 千手観音像 in Rengeōin 蓮華王院, Kyoto. Another form of halo called *ensōkō 円相光 enclosed the nijū ensō in a large outer circle, often seen on Aizen Myōōzō 愛染明王像 figures (1247), for example in Saidaiji 西大寺, Nara.