Kinsou no Vermeil: Gakeppuchi Majutsushi wa Saikyou no Yakusai to Mahou Sekai o Tsukisusumu

On the verge of failing his magic exam, Alto just barely manages to perform his summoning spell using a book he found by chance. However, the creature summoned following his incantation turns out to be Vermeil, a demoness previously sealed, so powerful that she can be compared to a true catastrophe on Earth. Completely subservient to Alto following the summoning ritual, the survival of the world now depends on the young man's future choices. How will he use the powers of his new familiar?