Hong Na-ri's life turns upside down when a man younger than her claims to be her step-father. Nan-gil, the self-proclaimed father, carries with him a dark past, but his fervent devotion to protecting Na-ri and her mother’s humble dumpling restaurant attests to his kind heart. Na-ri, the alleged step-daughter who is three years older than him, may be an oddball at times, but is always fit for duty once in her uniform. How did this unconventional family come about? A step-father and step-daughter, will these two find romance despite their seemingly impossible relationship? Their story unfurls as they embark on a dangerous and risqué journey.