The print immediately below is a famous Moronobu print of lovers in the pleasure quarters, intimately suggestive of sexual activity, but inexplicit. At bottom is a pornographic Moronobu print. It is said that Moronobu frequently published his prints in pairs, in one case showing lovers in their robes (note how in the example below, the samurai-lover still wears his sword (though it is, perhaps, for suggestive purposes), in the other, showing the same loves engaged in sex.
Note in the print at right that the woman is partially clothed. It is uncommon to see lovers completely naked, even in pornographic prints, and this seems to echo the Heian notion that the naked body alone is "without charm." (Note also the female voyeur at right, a common motif -- sometimes male -- in such prints.)