While the specific phrasing you used is often associated with adult or derogatory slang, there are several high-quality academic and analytical papers that explore the representation of characters in anime from a scholarly perspective.
: An exploration on Sabukaru Online of how Japanese media allows for a wider range of character archetypes and "gender spicing" compared to Western media. Important Terminological Note
: A detailed piece from The Artifice that breaks down characters who identify as women despite being misgendered by others, such as Lily Hoshikawa from Zombieland Saga .