Basically, a couple consisting of a very feminine-looking/acting boy and a very masculine-looking/acting girl. Often comes from pairing the Action Girl with the Non-Action Guy and with doses of Crossdresser, Bifauxnen, Ambiguous Gender, Attractive Bent-Gender, Unsettling Gender-Reveal, Viewer Gender Confusion, Dude Looks Like a Lady, Even the Guys Want Him and Even the Girls Want Her. Common in Gender Bender and "Freaky Friday" Flip series. Occasionally, House Husbands and their wives will fall under this trope.
Compare to Understanding Boyfriend, Pitbull Dates Puppy, and Violently Protective Girlfriend. Sensitive Guy and Manly Man, Tomboy and Girly Girl, and Masculine–Feminine Gay Couple work on a similar principle, but with two characters of the same gender. The Useless Boyfriend trope can be the result of this, but not always. Most likely are Cultural Rebels. Subtrope of Stereotype Flip.
Important Note: While this is usually a straightforward trope, examples can still get subjective in regards to whether or not the woman is masculine enough or if the man is feminine enough. Keep a few points in mind when editing:
Physical fitness and combat abilities relative to each other is irrelevant; what matters here is their comparative enthusiasm for these things.
If the boy is immature, it needs to be in a feminine way, and if the girl is mature, it needs to be in a masculine way.
The girl does not have to be a tomboy, and the boy does not have to be a sensitive guy. A Dark Feminine female and/or Noble Male can also invoke this trope.
Being ambiguously gay or ambiguously lesbian is not a requirement for the boy and the girl in question to fit this dynamic.
If the only context is that the boy is a wimp while the girl is action-oriented, it is not enough.
The girl and the boy in question do not have to be in a romantic or sexual relationship. All that is needed for them to qualify is that they know each other to some degree, and have personalities opposite to their respective genders' expectations.
