Authentic Edo period original, c.1855, Japanese erotic art surimono (privately commissioned, high-quality print) shunga woodblock print picture by Utagawa Kunisada II (1823–1880).  From his shunga series, Shunkyo karami-dako (Spring Games: Grappling Octopus)  
 
Shunga picture measures 9.2 cm x 12.2 cm.  Very good colors and impressions.  Very good condition with some light wear.  Album backing on reverse.  Please see and judge from photos.
 
A funny surimono shunga woodblock print picture as the male's female lover is intent on testing out the durability of his massive erection.  Although holding up well, he seems hardly enthused.