Intrepid adventurer Bell Cranel has leveled up, but he can’t rest on his dungeoneering laurels just yet. The Hestia Familia still has a long way to go before it can stand toe-to-toe with the other Familias of Orario — but before Bell can set out on his next mission, reports of a brutal murder rock the adventuring community! One of Bell’s trusted allies stands accused of the horrible crime, and it’s up to Bell and his friends to clear their name and uncover a nefarious plot brewing in the dungeon’s dark depths.

Alto Goldfilled, a diligent student at the Ortigia Academy of Magic, aspires to become a powerful sorcerer. But he is unable to become one as, despite his excellent grades and strong commitment to his studies, he fails his summoning class. With the threat of repeating a year hanging over his head, Alto tries following an old, worn-out grimoire in a desperate attempt to resolve his situation. To his surprise, he succeeds and summons a powerful demon named Vermeil. As a sign of gratitude for releasing her, Vermeil agrees to become Alto's familiar, sealing their relationship with a deep kiss. Little does Alto know what else he is capable of and what Vermeil's past hides.