The Jinni and the Isekai (The Jinni and the Isekai, #1‪)‬

Shiro Takeda, a samurai deep in debt and forced into a swashbuckler’s life, wanders in search of dungeons to raid so he can pay back his loans. Unfortunately, his lenders have already sent headsmen after him. His fortunes change when he finds a piece of legendary loot—a jinni lamp. But before the insolent spirit can bestow her gifts upon him, Shiro must find and kill the Jinni’s current master; a sultan of vast wealth, power and harems.

Perhaps with the help of his newfound companion, Shiro can discover who isekaied him into this strange land.