Following the events of K Missing Kings, the Green Clan JUNGLE has been spreading its influence, causing friction with the Red Clan HOMRA and the Blue Clan SCEPTRE 4. The war escalates when the Green King, Nagare Hisui, sends his men to attack Kuro and Neko, forcing the return of the Silver King, Yashiro Isana. Reunited with his friends, Shiro reveals his plans for dealing with the Green Clan —an alliance of the Red, Blue and Silver Clans! But the Green King carries his own wild cards!

Will the combined power of three kings be enough to stop Nagare Hisui from fulfilling his dark ambitions?”