A liquid discharger includes a head including nozzles to discharge liquid from the nozzles, a detachable first container attached to the liquid discharger to accommodate the liquid, a second container connected to the head to accommodate the liquid to be supplied to the head, a supply channel to connect the first container and the second container, an irreversible pump connected to the second container, and a controller to control the irreversible pump to pressurize and decompress the second container to reciprocally move the liquid between the first detachable container and the second container via the supply channel.