Mia Patton isn't how you would say, reasonable. She's stubborn, but she's also motivated. so when she goes to this little pub and goes on stage to sing, she's irritated by the stubborn boy holding her back. they both want to sing, not wanting to give in to the other.
so they sing together, that's that right? wrong, because Mia isn't the one for popular celebrities and specially not boy bands, she doesn't know that this stubborn boy is actually Harry Styles.
this unfortunate meeting leads to a series of events Mia wouldn't want to dream about. things like, having your own fans, hate, performing in a stadium, and of course Marry. and Mia is in the middle of this, together with a boy who is too stubborn.