The Japanese toilet is a thing of wonder. An array of buttons along the side of a typical commode allows you to spray and dry your rear, or front. Others activate oscillation or pulsation, and raise or lower the intensity of the gush. Some models feature a little deodorising puff of air freshener. The function that automatically puts the lids or seat covers down is referred to as the ‘marriage saver’. And then there is the heated toilet seat, which rivals Kyoto in full cherry blossom bloom as a highlight of a trip to Japan.