S-kyuu Guild wo Ridatsu shita Katana Kaji no Jiyuu na Henkyou Slow Life: Black Guild kara Kaihou sarete Kimama ni Kaji shitetara, Densetsu no Matou ga Umareteimashita

Sig worked as a versatile blacksmith in an S-rank guild. Fed up with the exploitative work environment, he decides to leave the guild! Sig, who loves forging katanas above all else, chooses to live a peaceful life in the countryside. However, the swords he crafts begin to influence the world!? The ideal slow life of the strongest blacksmith pursuing his craft at his own pace begins with a bang!

(Source: Starts Shuppan, translated)