This can only lead to one conclusion: Luffy is actually female.Originally Posted by Assertn
But seriously
I've been going back to previous chapters to try and figure out what could be on Boa back but nothing came up so far.
I would've guess that it was a scar she got from battling the Gorgon and was afraid to show people because it ruin her "beautiful" image but since a frame was dedicated to Luffy noticing the mark from somewhere suggest that it's not that simple.