Tasogare no Utsuwagami

Hana, a samurai who has lost sight of any goal other than survival lives a life of idleness in a huge underground prison city encounters Amanogawa Josui, an ayakashi vessel god, in the middle of a battle.

Hana makes a deal with Amanogawa Josui, who wants to return to the capital for a certain purpose, and decide to escape from prison and go on a journey.

(Source: Kadokawa, translated)