The World's Strongest S-Class Adventurer, Known as the Thunder Emperor, Shows His Power Without Restraint and Becomes a Warrior in the Magic Academy

Kaminari Tei to Yobareta Saikyou Boukensha, Majutsu Gakuin ni Nyuugakushite Issai no Enryonaku Musou suru
雷帝と呼ばれた最強冒険者、魔術学院に入学して一切の遠慮なく無双する

Adaptation

manga

Noah Oukrate, the S-Rank Adventurer known as the Thunder Emperor. As instructed by his master, the witch Sherah, he gets enrolled in a magic academy. There, he meets the daughter of the Duke, Claris, and the son of a fallen noble's house, Arthur. While working hard together with his classmates such as the A-Ranked adventurer Claris, he continues to be unrivaled at the magic academy with his thunder magic by his side!