Tell me how it ends

A girl that loves to read, a boy that loves to write. Who could be more perfect together?
Except, the boy isn't confident about his writing and the girl doesn't like to intrude.
One day she finds a notebook of his that someone took then discarded. She reads it only to find it missing an end, and is on the look out for whoever wrote it. He is on the lookout for his precious notebook so he can finally write the end.
The first time they meet, all she wants to hear from him, is how the story ends.
That was the day that he started writing how their story began.