Kim Jihyun was a 20 years old ordinary college student in Seoul who had been single her whole life. Her two older brothers - Kim Seokjin and Kim Namjoon, intend to change that by sending out her old love letters to 5 boys she had/has a crush on.  Life has never been the same since then.

When she escaped to New York City six years ago with their daughter, Kim Jihyun never thought she'd meet Jeon Jungkook ever again. But fate had its way of bringing these two ex-lovers who maybe, after all this time, had never really gone out of each other's lives at all.