Saihokuryou no Kaibutsu: Shakkin Jigoku kara Hajimaru Fukoku Kyouhei

Rodney, at a young age, has become the new lord of the Deder region—the kingdom’s northernmost frontier. However, what awaited him there was a hopeless hell of debt! In a desperate situation where even the prospect of repayment seemed impossible, he suddenly acquires "civilized knowledge from another world." Armed with modern knowledge, Rodney resolves to carve out a new future! Source: MU