A chess puzzle dating sim set in a world torn asunder by a century-long war—which the Schwarz Kingdom is set to lose until you and your twin are transported from our world and right in the middle of it, each holding a true game changer: magical crowns that give you the power to control the battlefield as a chess board. In one battle, you turn the tide of the war as you solve for the Schwarz army and defeat the invading marble Weiss soldiers—who, in return, kidnap your twin sibling. Take the crown and command the Schwarz army, bonding with their officers and royalty, to rescue your sibling and bring an end to the war!