Everyone has their own idea of what makes a good significant other. Sometimes it's looks. Sometimes it's age. Sometimes, you also just have to look at the person that's always been by your side...

No matter how much you love someone. Sometimes their habits can become too much...

Before leaving on his schedule overseas, Seongwu pens a series of letters to his girlfriend. What are their contents? He writes of events throughout their relationship that he wants her to look back on and remember. But on the last day, after she reads the last letter, what possible surprise could he have in store for her?