Moon Chae Won, Lee Sun Gyun, And Kang You Seok Team Up For Revenge In “Payback” Moon Chae Won, Lee Sun Gyun, And Kang You Seok Team Up For Revenge In “Payback” “Payback” has shared a sneak peek of three-way meeting between Lee Sun Gyun, Moon Chae Won, and Kang You Seok! SBS’s “Payback” tells the revenge story of those who risk everything to fight a money cartel that has colluded with the law. The drama gives viewers both thrills and catharsis through its portrayal of those who refuse to remain silent as they fight against incompetent and unjust authority in their own way. Lee Sun Gyun stars as reclusive money dealer Eun Yong, and Moon Chae Won stars as Army Major Park Joon Kyung, an elite judicial officer. Spoilers Previously in “Payback,” Eun Yong responded to the desperate call of Park Joon Kyung, who was like a sister to Eun Yong, and his nephew Jang Tae Choon (Kang You Seok), gearing up for payback while risking everything he has.