A discharger is configured to discharge liquid in a liquid channel to outside the liquid channel. The liquid is at least one of first liquid and second liquid different from the first liquid. An agitator is configured to agitate the liquid in the liquid channel. When executed by a processor, instructions cause the processor to perform: an introducing process of, when the second liquid exists in the liquid channel, controlling the discharger to discharge the second liquid to outside the liquid channel and to introduce the first liquid from the tank into the liquid channel; an agitating process of, after the introducing process, controlling the agitator to agitate the liquid in the liquid channel; and a discharging process of, after the agitating process, controlling the discharger to discharge the liquid in the liquid channel agitated by the agitator to outside the liquid channel.