Knight's & Magic is set in a world where medieval knights use giant robots called Silhouette Knights to fight against demon beasts, magical ravenous animals that devour everything on sight. The protagonist is Tsubasa Kurata, a mecha otaku from Japan who gets killed in a car accident. Tsubasa is reincarnated in this new parallel world as Ernesti "Eru" Echavalier, a boy born into a noble family. Tsubasa's previous otaku memories inspire Ernesti into creating his own Silhouette Knights in order to defend his kingdom.