Design originally done by scpkid (https://www.furaffinity.net/user/scpkid/), image done by rat-chan (http://rat-chan.tumblr.com/)
She/He/They/whatever all work - especially when they're wearing clothing with gender roles tied to them (like the kimono above has a female connotation), although Nara is most comfortable with "they". Definitely do not ask about their genitals or you will be kicked out faster than you can blink.
Nara is a problem solving witch. They're more or less the link between the natural and supernatural worlds in whatever story these characters end up in, although Nara is not the only witch in the world. Nara strikes up contracts between the spirit world (or whatever it ends up being called) and the physical world as a sort of mediator... who charges for the privilege. Anything from cheating boyfriends to interdimensional trade deals.