Short,quick storyline:
There are two sisters or brother (they can both be young adults or teens) one of the sisters/brothers is good, he/she is the most popular one and always is the one that everyone swoons for. He/she is the one who takes care of the house, cleans up and is neat and polite. The other brother/sister is the direct opposite he/she is mean, makes an enemy of everyone he/she meets and is generally jealous and mean to the other sibling. Everyone hates this second sim. But maybe can they switch? the good twin (over the course of the game) becomes bad and the bad twin becomes good or maybe at the end they both turn bitter or they both turn good?
END
Note: This isn't really a storyline but some way of gameplay that is based loosely off a storyline...hope you like it!