They are ohaguro (teeth blackening) tools. Blackening the teeth was an important custom among noble ladies and warrior wives in the Edo period. The black pigment used for teeth blackening was made by adding iron to gallnut powder to cause a chemical reaction. Mimidarai was named after the ear-shaped handles on both sides of the basin. This basin was used to keep the surroundings from getting dirty when applying black liquid to the teeth. It was also used to clean the mouth or hands. The wadai is a tool for adjusting the height of the mimidarai basin, and the nukisu was used as a cover for the mimidarai when the basin was not being used.