

Joseph, heir of a top-tier family, is forced by his grandfather—who threatens to kill himself—to agree to marry the eldest daughter of the Smith family. But Joseph refuses to marry a stranger. Determined to choose for himself, he changes his name, goes undercover as a nanny in the Smith household, and sets out to evaluate the looks and character of the family's four daughters.

Quila Yale, a double-award-winning actress, unexpectedly transmigrates into the role of the wicked stepmother, Lena Yale, from a show she once starred in.When a little kindness toward her stepchildren unexpectedly activates the "Mom's the Best System", she's able to provide lavish meals even during a famine. Through shared hardships, the children's suspicion turns into genuine love, finally seeing her as their true mother. By the time their father, the general, returns from war, this family is finally whole again.