Kuromame has been eaten to encourage the ability to work hard and lead a healthy life ("mame" in Japanese means hard-working and good health), because it was said that its black color has the effect of charming evil spirits.
黒には魔よけの力が有るとされていたので、まめ（勤勉）に働き、まめ（健康）に暮らせることを願って食べられた。