“Gods on the Floating Bridge of Heaven Watch a Wagtail.“
On this design: “...Eisen suggested this at the front of his massive pornographic compilation, the Pillow Library (Makuro Bunko), where the gods clasp each other on the bank of clouds, wagtail already to the left as Izanagi points his spear (Ill.134); two elemental peaks called Male Mountain and Female Mountain rise behind".
p.265 (Ill.134) in 'Sex and the Floating World: Erotic Images in Japan 1700-1820' by T. Screech. Antique Japanese color woodblock. Shunga (Spring picture).