Kajiya de Hajimeru Isekai Slow Life

One night, Eizo, a hapless corporate slave, saves a cat and gets hit by a truck. The cat which seems to be related to a parallel world, in return for his help, grants Eizo a skill of his wish and reincarnates him to another world. Eizo, who has craftsmanship as a hobby and wishes to use this skill for a living, chooses to be reincarnated as a blacksmith. And so he starts his life in another world as a blacksmith just as he wishes. However, Eizo's creations are at another different level that will shake this new world.

(Source: Kadokawa, translated)