Baek Sae Hoon and his wife, Lee Sun Young, desperately try to conceive a child but are unsuccessful. Sae Hoon's mother goes to Sun Young and asks that she consider surrogacy as a way of conceiving a child without Sae Hoon's knowledge. This is where Go Eun Nim comes in. She is their surrogate mother carrying their child, but things become complicated when she later falls in love with Sae Hoon's younger brother, Kang Ho.