From the late-'80s to the mid-'90s, Nintendo dominated the video game market, and Nintendo of America insisted that all games released on its consoles in the states follow their PG-13 “Video Game Content Guidelines.” This meant no "sexually suggestive or explicit content," among many, many, other restrictions, including no references to religion, alcohol, drugs, or politics. For JRPG fans, this meant a lot of censored Final Fantasy characters in America.
Final Fantasy censorship in the US began back in 1987 with the very first game in the franchise and lasted until Nintendo final loosened up in the N64 era. Since then, many of the games have, fortunately, been re-released on other consoles in all their uncensored glory. But even in the so-called eighth generation of video game history, a few sexy Final Fantasy characters were toned down in official artwork released in America. Since this is the Internet age, we can look at all the 16-bit midriffs and Harajuku Girl-inspired character sketches we want, worry-free. Enjoy!
Rydia was one of two characters from The After Years toned down for American players - but not in the game itself. The promotional artwork in Japan is far more revealing than what was released in America, with Rydia wearing a one-piece thong number with exposed sides. The Japanese art is actually truer to how she is depicted during gameplay, but the censored version of her outfit was used in the opening movie for the repackaged Final Fantasy IV: The Complete Collection in both regions.
Also Rankedsee more on Rydia
Goddess (Final Fantasy VI)
Japanese players fighting their way through Kefka's Tower in Final Fantasy VI had to take on the extraordinarily scantily-clad Goddess, one of three final bosses before taking on the Statue of the Gods and the evil Kefka himself. American players, apparently, needed just a little bit more left to the imagination.
Siren (Final Fantasy VI)
In Final Fantasy VI, Siren is a magical harp-wielding being known as an "esper" that teaches your party members magic while also casting a spell preventing your enemies from casting their own spells. In Japan on the Super Famicom, she's bottomless, and, tellingly, that spell is called "Lunatic Voice." In the American Super Nintendo release, she's fully dressed and the spell is called "Hope Song."
Porom (Final Fantasy IV: The After Years)
Porom's artwork was seriously toned down for America, with her sheer, lingerie-like top made far less transparent. The artwork is really the only time she appears like this: in After Years gameplay across platforms and in the Complete Collection FMV, she looks a lot more modest (as modest as you can look wearing a sheer pink curtain and thigh-high socks).