You and Hakyeon meet in an orphanage when you are little kids. You become best friends and promise each other you'll have each other's backs even if you get seperated. Hakyeon ends up getting adopted leaving you behind. Years go by and you reunite by accident. It turns out Hakyeon is now the son of the CEO of the most successful business in the country. You've moved on with your life and even have a new best friend, Jaehwan. Hakyeon tries his best to catch up but things aren't the same, you weren't the same little girl he knew so many years back. All you remember are all those promises that were broken and you want the past to stay in the past.