My Quiet Blacksmith Life in Another World (Manga) Volume 3 by Tamamaru

Eizo does his best to live a humble life, and the last thing he wants is to be caught up in political intrigue. But when he stumbles across a noblewoman in a precarious situation, he has no choice but to step in and lend a hand. This young woman turns out to be Diana Eimoor, daughter of the Eimoor comital family and the sister of someone Eizo has met many times: Marius, the city guard! Wait, Marius is a nobleman?! Though he’s stunned by this realization, Eizo agrees to help solve House Eimoor’s succession dispute by forging Marius a new family heirloom sword. However, danger looms when Marius’s brother launches a deadly plan to secure the countship for himself. Can Eizo forge a sword sharp enough to cut through the treachery surrounding the fate of House Eimoor?