After Seon-yoo's father committed suicide leaving behind a large sum of debt for them, Mother and 12-year-old Seon-yoo move to a new place to have new start.
Three elite North Korean sleeper agents live under cover for so long that they believe their cover stories are their real identities. They are shocked when they are ordered to kill one another or face death at the hands of an elite hit team.
Catching the eye of a wealthy gentleman, spunky Ha-won gets hired to live with his three immature grandsons so she can whip them into shape.
