Late one night, on his way home after a grueling day of physical labor, Hangyeom accidentally saves Jisu from almost getting hit by a speeding car. Jisu tells him not to worry, claiming she jumped between the cars on purpose, but Hangyeom gently urges her never to think that way again. Intrigued by Hangyeom, Jisu makes him a bizarre proposition: if he has sex with her, she promises to live for just one more day... A time-limit romance between a man who wants to live and a woman who wants to die!