Anna Katherine and Niall Horan have been best friends since their third year of college. They do everything together - endure Anna Katherine's overbearing mother, listen to their two best friends bicker every time they're in the same room, heal her broken heart after a messy breakup. They even live together. When Niall is about to get kicked out of the country, it just makes sense for them to deal with that together, too. Harry Styles and Natalie Thompson despise being in the same room as the other, but when they hear the plan that their best friends come up with, they decide to put away their differences and be the friends Niall and Anna Katherine need them to be. They didn't expect to actually begin to like each other.