Kyungsoo and Chanyeol are happily married with children. One day, Kyungsoo wakes up and finds himself 14 years in the past where he is still single and the children have not been born. Now, Kyungsoo has to make Chanyeol fall in love with him all over again. The catch is, they were enemies in the past and Chanyeol still despises Kyungsoo for a past tragedy.

Journalist Kyungsoo is out to uncover the dirt behind CEO Park Chanyeol who recently bought out his family's entire farmland in the name of "business". Other than finding himself helplessly attracted to Chanyeol, Kyungsoo may not be the only one who is spying on the other.

Chanyeol, a sorcerer, decides to use forbidden magic to survive in a world where magic is dying. Through dubious means, he “marries” Kyungsoo, another sorcerer. Chanyeol is just using Kyungsoo as his personal blood bank; but his plan backfires when he begins to fall in love with Kyungsoo and contracts the Hanahaki disease as a result of his unrequited love and unexpected feelings.

Kyungsoo has always adored his close friend, Chanyeol, ever since high school although they soon fell out of contact. Years later, Chanyeol is living his dream as a professional Go player and Kyungsoo feels settled as a doctor. They are reunited as adults and Kyungsoo discovers that Chanyeol now has selective mutism and has always been alone all these years. Kyungsoo decides to step in and help Chanyeol and restore the relationship they once had.