Small Stationary or poseable Statues or Dolls representing Anime, Game, or Manga Characters. Many Have removable clothes, or other apparel that have Nudity Underneath. (Some Don't). Some Represent General Anime, and some Ero-Anime, Or of Regular Games or "Eroge" (Hardcore Date/Sex Games).
EXTRA: Some seem to be of questionable origin,since some of Nude ones Feature characters that are "NOT" (Meaning "NEVER"), nude in their other Mediums. (See also: "Dakimakura").
(Above by EdBum14: 8-9-14 1:24am)
EXTRA-2: Some Nude Figures are Known as "Makaizou" figures. (Meaning they were non-nude or semi-nude [topless] figures, modified by a third party to add bare nipples and areolae, and/or a vagina and anus, mostly without the originator's consent. These figures are mostly frowned upon by the originators, AND the Japanese Authorities, but, are made, sold, and bought anyway!) SEE TAG: 'makaizou_figure'.
NOTE: When the tags 'figure' and 'photo' are combined, it shows actual figures, and not just ones drawn as part of Anime/Manga/Eroge etc.