Evan wakes in agony, reborn ten years into the past — as the lowest handyman student at Blackthorn Magic School. In his past life, the Ministry of Magic slaughtered his entire family to seize the castle his ancestors founded. Reborn, he binds the "Magic Grimoire Bond System": form guardian contracts with pure-hearted women of special magic talent to unlock hidden areas of the castle and amplify his power a hundredfold. He contracts ice-cold curses instructor Isabella, animal-speaking Lina, and elven princess Irina — fighting from handyman to legend. But this draws the attention of the Ministry's corrupt leadership: they ally with dark wizards, throw Evan into a dungeon on charges of "forbidden dark arts," and strip the three contract maidens of their magic, imprisoning them. In the depths of the dungeon, Evan uses his bond network to bypass the seals, awaken the castle's core "Heart of Blackthorn," and become the castle's master — commanding gargoyles and ancient defenses to fight his way out. At the execution ground, he kills all enemies and exposes the Ministry's castle-seizure plot. In the end, he takes over Blackthorn School, forging it into the most powerful independent magic fortress — with his girls as the unseen supreme rulers behind it all.
