 Galbraith defines "shōnen-ai" as "original content that can approach serious literature in tone and theme", as opposed to a more light-hearted "yaoi".By the late 1980s, the popularity of professionally published "shōnen-ai" was declining, and "dōjinshi" (self-published) "yaoi" was becoming more popular.The terms "yaoi" and "shōnen-ai" are sometimes used by Western fans to differentiate between two variants of the genre.