No, the official Japanese is indeed Aerith. Her name is a japanese transilliteration of the word "Earth", which is japanese is Earisu, and translated back was SUPPOSED to be Aerith. The Japanese don't have a 'th' sound in their language, and replace it with 'su' instead. Aeris is translation fail from the original game, which is why in every FFVII she's appeared in since has listed her as "Aerith". There are so many translation fails and typos in FFVII it's almost sad xD Like Jenova's only line in the entire franchise being "Beacause Cloud, you are a puppet." Wow Squeenix, wow. xD