Formerly, people used to stay awake during the night of joya to welcome the god of the incoming year, due to a superstition that they might get gray hair or wrinkles if they went to bed at an early hour that night.
かつては、除夜は年神を迎えるために一晩中起きている習わしがあり、この夜に早く寝ると白髪になるとか、皴が寄るとかいった俗信があった。