Peddler in Another World: I Can Go Back to My World Whenever I Want (Manga)

Shiro Amata left his toxic job and moved into his inherited house from his grandmother’s will, discovering life-changing truths shortly after. Firstly, that his grandmother was a witch from another world, and secondly, that this world was accessible through her closet door! Shiro was also gifted an all-powerful skill called “Equivalent Exchange” through a book his grandmother left for him. This skill allowed Shiro to exchange money between his world and the otherworldly currency.
With his new skill, Shiro planned to make a fortune by selling convenient items like matches to the vibrant inhabitants of the other world, utilizing goods from his world. His objective was to become wealthy enough that he never had to work another job again.