Pokemon X and Y Tutorial – How to Start New Game Erase Delete Save File and Trade Guide
If you want to reset your game’s save file: Once you get to the screen where you select between New Game, Saved Game, et cetera, press B, Up, and X. This will cause your save data to delete, and you will have “restarted” your game. There is also the “Soft Reset”, commonly used by people who hunt for Shiny Pokemon.