Actually, no that's not the proof. The PROOF is that in the original it is revealed (after quite some time) that they are twin brothers. But the end result is the same. BTW- I was stunned to see just how much people argue over the gender of Dorii and Guraa on this site! It seems like half the posted pics of them have some long-running flame war about it. I mean, people shouldn't feel stupid for thinking that they were female. They were intentionally DESIGNED to fool the audience, that was the whole point. Obviously not many people have actually seen the anime or they wouldn't be fighting about something so trivial.