erotic prints (shunga - 春画) (genre )
It is often difficult to ascribe a particular shunga print to a specific artist. More often than not erotica was not signed and there were almost none that had a publisher's seal, because this would endanger both the artist and the publisher with punishments meted out by the more conservative elements of the government. And yet, nearly all major ukiyo artists produced such works.
Abuna-e (あぶな絵) are a category of shunga which are more suggestive than explicit.