In Florida, I have only ever seen someone wear a cape to dress up as a superhero. However, since that is rather weird, I doubt that that is what is meant here. Is "uma capa" more like a winter cloak, or is it actually just a frivolous piece of fabric wafting at your back to make you look like Batman or Superman? I seem to recall that in Tess of the D'Ubervilles, she wore a cape, and so I am thinking a cape may be a form of winter clothing of which would be unfamiliar to me as a Floridian.
Well, depending on your age, you might be interested to know that Porto in Portugal helped set the stage for Harry Potter and that included the Hogwart's school uniforms with their capes. In Portugal the university students are colloquially referred to as morcegos or bats (so kind of Batman-ish).
This is a Tuna Group (most have their capes over their shoulders because they are so warm, which is welcome in the cold Portuguese winter where most houses are unheated – the patches are earned somehow, and the capes are purposely torn to signify a romantic relationship while in university... so that some have several tears by graduation, that are then sewn up again):
You can listen to some of the girls here (some whom are wearing their capes):
And a mixed group (most have their capes in front of them cause capes have many duties including holding things down in the wind):
But there is a fashion here too for the cape-like coats such as these:
So many more designs! All cape-ish.
Even the boys:
As a bonus, here is the bookstore that inspired many of the Harry Potter sets: