Isekai Toushou no Maken Seisakugurashi

One fateful day, unknown blacksmith Lutz accidentally forges a truly exceptional katana: his life's magnum opus. However, a certain incident forces him to give up the blade. To make matters worse, he forgot to stamp his maker's mark on it, making it impossible to prove that he crafted it. Meanwhile, the katana falls into the hands of Gerhardt, the local lord's personal spellforger. The moment he picks it up, he is enchanted by its beauty... In this sword-making tale, an obscure blacksmith and a nameless katana move the hearts and fates of people! (Source: Square Enix)