High atop the tallest spire of the Mage's Tower, the esteemed sorceress Ruby, accompanied by her diligent apprentices Sarah and Maria, dabble in the darkest magics and arcane lore to summon forth a formidable demon to bend to their will. But when the ritual takes an unexpected turn, they accidentally summon Lilith, the seductive and insatiable futanari succubus, the head secretary to the Demon Lord himself.
Unable to return to the underworld until a binding pact is sealed, Lilith strikes a deal with Ruby: she will impart forbidden knowledge in exchange for three things - souls, magical gems, and... a cat?
Eager to harness such unparalleled power, the deal is sealed, unaware of the true cost of their desires. As it turns out, Lilith, a creature of boundless carnal hunger, demands much more than mere trinkets and relics. The trio must now deal with Lilith's lustful demands and sensual challenges to fulfill their end of the bargain, or risk facing dire consequences.