Isekai Madou Koshoten: Cheat Maryoku Aru kedo, Mattari Tenin suru Koto ni Shita
異世界魔導古書店 ～チート魔力あるけど、まったり店員することにした～
After defeating the demon lord as the most powerful ability user on Earth, Takuto is reborn into a new world. He is discovered by Kuraramela, a goddess who owns an antique bookshop. Upon turning 14, he begins using his inherited power to manage the shop, which contains many dangerous magical tomes. One day, a silver-haired woman visits and is intrigued by his mixed success in handling the shop's challenges. She makes a request, and Takuto agrees to help.