For the sin of falling in love with a human, Gumiho gives birth to a daughter and enters the world of humans in order to protect her young, tender child. However, Yun Dusu, the man who chose her, is the father of a dying daughter. In order to obtain a liver to save his beloved, illness-stricken daughter, he is forced to do the unthinkable: to kill Yeoni, the daughter of Gumiho. Unaware of this fact, Gumiho opens her heart to Dusu, who protects her as if she is family, and once again falls in love with a human, ultimately suffering for it. And the one man who falls in love with Gumiho, a nonhuman with more humanity than any human, realizes he truly loves her and attempts to make their love work.