I'd just re-install the game.
Chat with our AI personalities
Play the game til u discover it
you have to uninstall the game and then reinstall it
I don't think you can restart one story, but you can reset the whole game without uninstalling. It will tell you on the first page of the manual thingy.
just look at riley's goals to see what she is thinking (or hoping) to do. for example, if she wants to go with her friends to he gym- then take riley and her friends to the gym. so basicly, look at her goals to see what she wants to do, and before you know it- you've completed riley's story! ;)
You have to uninstall it and then Reinstall it. It really stinks but that's what i did once to restart something that I messed up. If anything, Try this and this is the only thing that I know how to do it. Sorry!! Hope this helped!!