Authentic Meiji period original, c.1899, Japanese erotic art shunga woodblock print crepe picture by Terazaki Kogyo (1866-1919).  From his shunga series, Izumo no chigiri (Pledge of Izumo).   
This particular shunga piece is the the most famous of the series and highly regarded as one of the standout shunga artworks of the Meiji Period specifically titled, "Seaside Ecstasy."
 
Shunga picture measures 25.7 cm x 19.1 cm.  Excellent colors and impressions!  Condition is very good with minimal wear to note of.  No backing.  Please see and judge from photos. 
 
This is considered the Meiji Period iconic shunga piece, much like Hokusai's Octopus-themed shunga artwork, Dream of a Fisherman's Wife is to the Edo Period shunga genre.  
 
"A Meiji era masterpiece featuring a young couple wearing the latest fashion making love while standing in shallow water."  excerpt from p.472 in Shunga, Sex and Pleasure in Japanese Art by the British Museum ( Timothy Clark & C. Andrew Gerstle)