Last August 15, Kingdom mangaka Yasuhisa Hara attended a roundtable discussion with Game of Thrones showrunners David Benioff and D. B. Weiss.
Hara admitted that he insisted that the live-action Kingdom movie have the character of Sei Kyou take inspiration from none other than the much-hated Joffrey Baratheon!
As for the Game of Thrones showrunners, Benioff and Weiss also showed some love for Kingdom.
He also added that Sei Kyou holds the key for the live-action Kingdom film.