kaioke 貝桶

Shell buckets. Paired octagonal wood-based lacquer-decorated containers with fitted inrōbuta zukuri 印籠蓋造 lids used since the Heian period for storing shells *kaiawase 貝合 (shell-matching game). One box would hold the 90 painted dashigai 出貝 (face-up shells), the other the 90 painted jigai 地貝 (face-down shells). Because of the double-ridged lines encircling the kaioke, they appear to be stacks of three differently-sized boxes . The box forms and game rules were set by the 16th century. Kaioke were an integral part of daimyō 大名 trousseau as symbols of conjugal fidelity because each shell had only one match. More recently, kaioke are used as a decoration for the Doll's Festival.