Louis Tomlinson is infuriated by his grumpy neighbor, Harry Styles, who can't even be pleasant when they bump into each other.
So on the suggestion of his best friend, Niall Horan, Louis concocts a plan. He starts a blog in order to clinch his perfect job, and now he has a subject. Over the next few days, he is going to kill Harry with kindness - and Christmas cheer - and document it for all to read about.
But as the experiment goes on, Louis realises he underestimated the effect it would have on Harry, and on their relationship, and things take an unexpected turn . . .