I haven't read the rules of the contest but yeah, I know there's one, I visited the Tumblr site before post the comment, but I just gave it a glimpse.
I haven't read the manga either, I just watched the movie a couple of times, so I was wondering how important is to stick to the rule of same-gender-characters in the case of Akira (in the movie is not that important the sex of the character, cause as you pointed out, he just appears briefly).