Utsuho reiuji, not normally shown as quite that muscular but still the largest playable character in Touhou 12.3 and the hardest hitting by nature. But that was the first decent pic that popped up when I searched Touhou navel.
Huh.... If it didn't have the mature context, you'd think you'd be listening to a decent children's song. The comments on the Youtube page are also worth a laugh. If you can post a picture of her navel then i'll forgive the navel-less post.
Ah the magical world of gaming... and seeing it occupied by those of the opposite gender. True of most people and their hobbies/interests I'd imagine. Gaming does have that certain... variety, to it though with all the different types of games and settings and stuff that you'll find in them.