In the late 1970s, shōjo magazines devoted to the new genre began to appear; and, in the 1990s, the term boys' love or BL was invented for the genre, which replaced earlier terms such as tanbi, shōnen ai and juné in Japanese usage.
Akiko Mizoguchi describes its application to male-male stories as "misleading", but notes "it was the most commonly used term in the early 1990s." and were replete with "philosophical and abstract musings".
Anal sex is a prevalent theme in yaoi, as nearly all stories feature it in some way.
The storyline where an uke is reluctant to have anal sex with a seme is considered to be similar to the reader's reluctance to have sexual contact with someone for the first time.
The main characters in yaoi usually conform to the formula of the seme (the "top", or dominant figure) who pursues the uke (the "bottom", or passive figure).
Material classified as yaoi typically depicts gay relationships between male characters and may include homoerotic content.