Kōsai made this basket with bamboo and rattan, using the techniques of twill plaiting on the base and parallel-line construction on the body. Incised signature on the bottom reads Kō.
The basket comes with its original lacquered bamboo otoshi (water container) and original fitted wooden tomobako storage box inscribed outside “Clear Stream” flower basket and signed inside "Made by Kōsai"; seal mark: Kōsai
Tanaka Kōsai was born in Kaga, Kanazawa Prefecture but the family moved to Kyoto and at age 15 he was apprenticed to Kameyama Kochikusai (1877–1937). He specialized in baskets for the tea ceremony.