In Japan, they're called "otokonoko" or "otoko no musume" (男の娘), which literally means "male daughter".
They dress as females, but they're not necessarily gay—or straight, even—for that matter. While certainly not mainstream, the otokonoko subculture has garnered fans in geek areas like Akihabara, spawning magazines and even a cafe staffed by otokonoko.
So when gamers noticed that Atelier Ayesha character Regina Curtis seemed to be packing a hidden bulge under her skirt, they quickly began saying she was an otokonoko. Keep in mind, the game does not refer to Regina as an otokonoko, and her gender is female.
I'm not entirely convinced, and this seems to be a matter of seeing what one wants to see. Still, online in Japan, many didn't seem bothered by trifles like that, and wrote that Regina being an otokonoko made them want Atelier Ayesha even more. "Well, I'm glad she's an dude," wrote one. "I can buy this game in good faith."
Atelier Ayesha came out in Japan late last month. Buy it in good faith.
『アーシャのアトリエ』 で男の娘発見ｗｗｗｗｗｗｗｗｗｗｗｗ [オレ的ゲーム速報]