water dish
A water dish, more formally called a sara (皿) is an anatomical feature of the mythological kappa. It is an indent in the top of a kappa's head that retains water or other liquids, which is said to be a kappa's life force. If the water in a kappa's water dish is spilled, it will lose its strength or possibly die.
Tricking a kappa into spilling the contents of its water dish with a deep bow is said to be the only way to defeat a kappa, as it is obligated to return the gesture out of politeness.
This tag has been aliased to water_bowl (learn more).