I Become a Legendary Arch Mage by Reading a Book

300 years. That was how long it had been since he had last been opened. For 3 whole centuries, the mysterious book of magic, also known as Grimoire, has been stuck on the shelf of the Le Temis Royal Academy Library.

Just then, an apprentice mage opens the Grimoire, only to die in a freak accident. As the dismayed Grimoire awaits his teleportation to a new location, the library door creeps open and a mysterious girl, Riley, approaches and opens the Grimoire, becoming his new contractor. (Source : LINE Webtoon)