What will happen when a promise gets brought up from the past after being forgotten over the course of 12 years?

A summer has come and gone since Voldemort was defeated. Hogwarts has been rebuilt. The Golden Trio return to Hogwarts to complete their education. They can all finally lead a normal life. But for Hermione, life is anything but normal. While Harry and Ginny were still going strong, her relationship with Ron hadn't lasted long. Harry knows that things didn't work out with Ron and Hermione. But little does he know that he's the reason why.

In their 6th year at Hogwarts School of Witchcraft and Wizardry, shortly after Hermione realises she is smitten with Ron, he begins dating Lavender Brown, and Hermione is devastated. As her best friend, Harry makes a brash decision and tries to help Hermione the only way he knows. The plan is to pretend that they are a couple in hopes that Ron becomes jealous, but the temporary "relationship" quickly gets out of hand. *For the purpose of this story, Voldemort was killed in The Battle of The Department of Mysteries.* started: 2013 finished: 2014