Go Eun Nim (Lee Soo Kyung) is struggling to become a teacher while supporting her poor family and taking care of an ailing father. With no other options, Eun Nim agrees to become a surrogate mother for Baek Sae Hoon (Ryu Jin) and Lee Sun Young (Go Eun Mi), who have been trying to have a baby without any success. But Sun Young is having Eun Nim be her surrogate without Sae Hoon’s knowledge but with her mother-in-law’s blessing. Sae Hoon, meanwhile, falls for Hong Yeon Hee (Lee Shi Young), a woman he works with, and starts having an affair. Despite her commitment to carry another couple’s baby, Eun Nim’s life becomes even more complicated when she falls in love with Baek Kang Ho (Jung Gyu Woon), Sae Hoon’s half-brother. Kang Ho is already a black sheep in his family as the love child of his father’s philandering. Can he and Eun Nim possibly be able to act on their love under the impossible circumstances?