Lee Jung-woo, the CEO of the Lee Woo Group, was destined to die before turning thirty after being poisoned with a deadly toxin in his childhood. However, he discovers that Jang Ah-rin, a poor college student, is the world's only 'antidote' capable of healing him. Their marriage begins with a fateful encounter, but he proceeds with the treatment without knowing that Jang Ah-rin's life will be endangered if she cures him. He attempts to detoxify the poison through physical contact after taking a special herbal medicine from a shaman. However, Jang Ah-rin gradually starts coughing up blood and collapses. Upon realizing she was merely a tool for his treatment, Jang Ah-rin, who has genuinely fallen in love with Lee Jung-woo, falls into deep despair.