Kōgō are small lidded containers for storing incense. Another japanese name is kōbako 香箱 („incense box“). During the japanese tea ceremony the kōgō is brought into the tea room on a tablet when preparing the charcoal (sumitemae 炭手前). The incense is then placed near the charcoal and the container decoratively positioned on a shelf. In a shorter variant of the sumitemae the kōgō is just placed decoratively in the decoration niche of the waiting room (machiai 待合) on a small cloth, the so-called kobukusa 古帛紗, or a special mat made of several layers of paper (kamikamashiki 紙釜敷) for charming the guests eyes.
Although kōgō are quite small objects they enjoy a great attention through connoisseurs. Like most others tea utensils kōgō too are distinguished according to their origin. But this mostly gives more a mere orientation about the origin of the technic instead about the origin of the art piece itself. On the one hand there are the chinese pieces (karamono 唐物). They include those objects made of black and red carved lacquer, lacquer ware with mother-of-pearl inlay, blue painted porcelain (sometsuke 染付け) or the three-colored Jiao-zhi ware (kōchi-yaki 交趾焼き, from a today’s region of Vietnam). On the other hand there are the Japanese pieces (wamono 和物), like Japanese pottery, lacquer ware associated with Japanese technics like gold painting (maki-e 蒔絵) or lacquers with a foundation of Japanese paper (ikkanbari 一閑張り) as well as kōgō made of different woods, also gourd et al.
Furthermore the material dictates the usage of the kōgō depending on the season. Since different incense is used in summer and winter and – according to that – a different container. Kōgō are then also distinguishable from those used only in summer, when a portable brazier is used (furoyō kōgō 風炉用香合), and those used only in winter, when a sunken fire-place is used (royō kōgō 炉用香合). In summer kōgō made of lacquer or wood go along light aromatic woods. But in winter you will find predominantly pottery kōgō. This is due to the usage of nerikō 練香 in the colder season – an incense made of essential oils like musk or agar wood mixed to a paste with honey or sugar. In order to avoid the material absorbing the scent when using nerikō it is common to use a camellia leave to cover the inside of the kōgō. Shell, metal or even ivory made items can generally be used for both seasons, but they are mainly found in the preparing room (mizuya 水屋) for storing the incense.
For delivering insight into the tremendous number of types and variants of the modelled kōgō, the Katamono kōgō ichiran 形物香合一覧 („Chart of kōgō models“) was published as woodblock print in 1855. This paper lists some 230 various designs ranging from a lot chinese examples (215 in total), some lacquer works (3), the most representative japanese pottery works (7) and a few more. The funny thing is, that the listing is arranged in the manner of a traditional sumō-banzuke 相撲番付 – a ranking for popular japanese sumo wrestling.