So Jin, a genetic researcher who loves DNA, decides to end her relationship with a playboy boyfriend and sets out to find a genetically compatible partner for a happy relationship. Whom among the two men that So Jin meets, obstetrician-gynecologist Yeon Woo and firefighter Kang Hoon, will be the perfect match for her? A captivating story intertwined with genetics! This story portrays the struggles, love, and everyday lives of young friends.

Jung-yoon was approached by a random stranger named Jun-woo, who told her she'd be dead in six hours. As she follows him for answers, she begins to question whether he's her savior or the one trying to put her in danger.