The series tells the story of Yoon Hyun-woo (Song Joong-ki), a loyal higher-up employee working for chaebol Soonyang Group, who was betrayed and murdered by a member of the Soonyang family to cover up a tax evasion scheme. Hyun-woo later wakes up in 1987 discovering that he has been reincarnated into the body of Jin Do-jun, youngest grandson of the Soonyang family. Using these circumstances to his advantage, he starts his revenge by plotting a hostile takeover of Soonyang Group. - wikipedia