My Isekai Life 03: I Gained a Second Character Class and Became the Strongest Sage in the World! (manga)
Yuji passes the adventurer guild's exam with flying colors and signs on for his first harvesting quest. But the world's greatest Sage is no slouch, and Yuji's unimaginable efficiency bowls over the guild staff! And with a slew of demons soon threatening unprecedented havoc over the quarter, the guild will be thanking its lucky stars to have Yuji among their ranks!!