Ikusei Skill wa Mou Iranai to Yuusha Party wo Kaiko Sareta node, Taishokukin Gawari ni Moratta [Ryouchi] wo Tsuyoku Shite Miru

With the hero's party having grown past the need for his training skills, the protagonist Aega finds himself sacked. In lieu of a cash severance pay, he's granted dominion over the territory of Tokumo. However, his new domain may hide a shocking secret...!

(Source: Manga UP! Global)