Baek Ho and I Seul are childhood friends. They have known each other for twenty years. They have feeling for each other but were never able to confess them. Now I Seul is getting married and Baek Ho regrets that he never expressed his feelings. He gets the chance to travel back in time to fix some of the biggest mistakes in his life. Will these two be able to have a happy ending or an have even more messed up life?