Chun Kang-il is a 911 rescue worker who refuses to love anyone since he lost his wife. Tortured with guilt and regret that he wasn’t there for his wife when she’s dying, he loses all his will to live. Mi-soo is a surgical doctor who would do just about anything to achieve her goal, with no interest in love. One day, she is sued by patient’s family because of her wrong diagnosis and needs a witness not to lose her license, and that witness turns out to be Kang-il. Although she discovers that she was the very doctor who lost his wife on the operating table in the past, she tries to get close to him with the ill intentions only to use him as her witness and finally volunteers to be a paramedic at his fire station. One night, at the scene of a car accident inside a dark tunnel, Mi-soo sees Kang-il saving a bundle of small helpless yellow chicks. She thinks, “Perhaps, he could be the one.” One night, finding Mi-soo who fainted on the streets by chance, then finding the same woman at a suicide attempt on top of a bridge, Kang-il thinks, “Definitely not her.” But he can’t help but liking her presence around him with her peculiar actions. Cold-hearted Mi-soo is able to feel emotions through him, and Kang-il is able to open his heart for love again.