Authentic Edo period original, c.1845, Japanese erotic art shunga woodblock print picture by Keisai EISEN (1790-1848).  From the shunga series, Harujo Sumida Hakkei (Eight Views of Sumida in Spring).  Shunga picture measures 18 cm x 12 cm.  Very good colors and impressions, as well as in very good condition with just some light wear & soiling.  No backing.  Please see and judge from photos.
 
It's always difficult to come across shunga woodblock print artwork showcasing anal intercourse, especially between male and female.  In this scene, the woman is being penetrated anally, while both she and her male partner manually pleasure her vagina.