When two worlds collide [Niall Horan Fanfic]

Niall and Ellie had never spoke to each other in their life, until he is moved next to her in maths, and they turn out best friends. It turns out they live in the same street but their families cannot stand each other, that's why they've never noticed each other before. Her dad and his mum refuse to let them be friends, due to an incident that happened in high school. What will they do?