One day, Teruto Kurabe is wandering around the city with a piece of bread in his hand, and discovers a girl named Sakura Banka who is being attacked by a thug, so he uses the power of a mysterious card in his possession to save her. Witnessing his powers, Sakura speculates that Teruto must be highly skilled in Build-Divide and requests a battle with him. She has been searching for a powerful player that could help her win through the Rebuild Battles, which would allow her to challenge the King. However, Teruto has lost all his memories…