Years after having been exiled from the Kannagi household for being unable to utilize their fire magic, Kazuma returns to Japan, only to discover that the Kannagi family's very existence is threatened. Unknown to them, during his absence, he had become a Contractor and thus acquired a vast strength in wind magic. Not showing any remaining contempt for them, he offers to help solve the Kannagi household’s problems in return for large sums of money. Together with his younger brother Ren and the feisty heir to the Kannagi household, Ayano, he fights to protect those he cares about... for a price!
Following the war against Albion, Saito has returned to the Tristain Academy and is becoming increasingly closer to Louise. However, their newfound tranquillity is shattered when one day, the runes on the back of Saito’s hand disappear. Saito is now free from being Louise’s familiar, but not from her ‘explosive’ temper. Nevertheless, Saito refuses to leave Louise’s side and pledges to help her find a way to renew their contract and regain his powers. Soon, while on a mission to find the elf that revived Saito during the final battle against Albion, the duo encounters the mysterious Sheffield: a familiar of another void magic user. Why is Sheffield pursuing the pair and what plans does her master have for them?