Itsudemo Jitaku ni Kaerareru Ore wa, Isekai de Gyoushounin wo Hajimemashita

Shiro Amata leaves his job at a demanding company and inherits a house from his grandmother. He later discovers she was a witch from another world, with that world accessible through a closet door in the house. Using a book she left behind, he gains a powerful ability called “Equivalent Exchange,” which lets him convert money between his world and the other. He begins selling everyday items from his world to the other’s inhabitants, aiming to make enough profit to never need work again. The story is based on a light novel.