To provide a toothbrush which enables even toddlers to perform tooth-brushing with pleasure, and which can make the toddlers naturally have the habit of tooth-brushing.

An implanted section 1a and/or a handle section 1b of this toothbrush 1 has a primary layer 11 on which a design 11a is drawn and a secondary layer 12 which is printed with a water reactive agent in a manner to conceal the primary layer 11.