Japanese Sake bottle

I found this sweet little sake bottle and cups in an antiques shop in Machynthlethh, so unexpected. When you drink the last drops you can see a shadow of a Geisha girl in the bottom of each cup. The porcelain is moulded so that the thicker areas form the darks and the thinner areas are lighter. I have also read that below the bird perched on the top, is a hole and under that is a whistle which should sound when you fill the bottle, shake it and whilst pouring out the sake. Sadly mine must be a modern copy of a traditional design but lacking the integral whistle.