Smurfette syndrome

The sexist narrative trope of having only one female character in a group consisting of a large number of male characters.

It relates to tokenism and exceptionalism.

Origin

The name comes from the fact that there is only one female character, la Schtroumpfette (the Smurfette), in the entire village in Les Schtroumpfs (The Smurfs), a Belgian comic book series (later made into the English-language cartoon). (A second female Smurf called Sassette came in later, but this still leaves a superlatively unbalanced gender ratio.)

Both the Smurfette and Sassette were magical creations added to a pre-existing, all-male Smurf community.

Incidence of the Syndrome

(Examples here)