"Hello, I'm Isana Shiro." A gentle smile appeared at the corner of the young man's mouth. He lifted the pink-and-white fluffball in his arms. "This is NEKO."
The premise of this story: Isana Shiro isn't the White King, Shiro. He's the Isana Shiro whose body was used by the White King before he was reborn, and the older brother of the Colorless King, an original character who is Isana Shiro's younger brother. The story takes place after the original plot ends. The protagonist is reborn just after Miwa Ichigen's death, before Isana Arashi, an original character, becomes the new Colorless King. Also: the Green King is reborn (crossed out)... Read the first chapter and you'll see. Hmm, who should the pairing be? The Red King, Green King, Blue King, Shiro, or Arashi-chan? Not that I’d ever say it might be someone outside of K. lol
I finished reading it with a confused look on my face and didn't understand anything.