Noroma Mahou to Yobareta Mahoutsukai wa Juuryoku Mahou de Musou suru: Mada Juuryoku no Gainen no Nai Sekai Nite, Shounen wa Banyuu Inryoku Ou to Naru

Wade, a boy born in the slums and raised by terrible parents, finds a glimmer of hope when he becomes an apprentice adventurer. Enduring grueling training, he's promised to be taught magic if he perseveres. On the day of his fateful magic instruction, while others are granted promising fire and water magic, Wade receives what seems like the worst of luck—a magic called "Slow Magic."

In despair upon realizing it's a spell that makes him clumsy, Wade recalls memories of his past life as a corporate slave. "Huh? 'Slow Magic'? That sounds like gravity magic, a powerful spell!"Yes! In this underdeveloped world, where the concept of gravity is largely unknown, Wade is underestimated.

(Source: Kadokawa, translated)