Lemon is a term used in reference to anime and manga, especially fanfiction, to describe material with explicit sexual content, such as hentai, yaoi, and yuri.

Some have elaborated this into a string of different terms involving citrus to describe the "rating" of a particular piece; a hint of citrus indicates subtle innuendo, etc. The most common derivative is lime, which denotes sexual content that is not quite explicit. A rarer tongue-in-cheek term is pineapple to refer to a story with various bizarre kinks. The use of this term (and its derivatives) is increasing in non-anime fanfiction communities.

The term is derived from the anime video series Cream Lemon, a historically important sexually explicit anime (though not quite the first).