The Rider Fight (ライダーの戦い Raidā no Tatakai) is a great battle in the Mirror World where 13 Riders are to do battle with each other until only one of them survives. The victor in this grand Battle Royale will be granted his/her wish. The battle itself was discovered and used by Yui's older brother, Shiro Kanzaki. Although the victor is awarded with the wish, Shiro manipulated the war for his own. In actuality, Shiro plans to become the victor so that he could wish for Yui's well-being.