The Iceblade Sorcerer Shall Rule the World 6 (manga)

A commoner from the countryside, Ray White finds himself surrounded by the children of aristocrats at Arnold Academy of Magic. Fortunately, he quickly befriends the talented daughter of a noble house, a half-elf short on self-confidence, and a friendly musclehead. Together, the four take on their first practical test in the Kafka Forest.

But hey, wait! How did a seemingly talentless commoner like Ray get into Arnold Academy in the first place...?