I Was Dismissed from the Hero’s Party Because They Don't Need My Training Skills, so I Strengthened My [Fief] Which I Got as a Replacement for My Retirement Money.

Ikusei Skill wa Mou Iranai to Yuusha Party o Kaiko Sareta no de, Taishokukin Gawari ni Moratta "Ryouchi" o Tsuyoku Shite Miru
育成スキルはもういらないと勇者パーティを解雇されたので、退職金がわりにもらった【領地】を強くしてみる
From Leveling Up the Hero to Leveling Up a Nation

Adaptation

manga
2020
Publishers:
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*