Fuukan no Grasesta

"Grasesta, City of Interception", capital of the Kingdom of East Gohdia.
The city was built atop the subterranean labyrinth known as the "Black Pit", a remnant of the once thriving Demonic Lands of Samara, whose infamous name has been carved deep into the annals of Western history.
In order to defend the holy barriers keeping the "Blockaded Expanse" sealed up, the city, being the central hub of retaliation against the most fearsome of the Demonic Lands, requires vast amounts of manpower to be brought in to replenish its forces in the ongoing onslaught.
These reinforcements consist primarily of slaves that were sold from other countries and mercenaries that flock to the area in search for a chance at fame and fortune, soon turning the city into one whose populace had only one thing on their mind: treasure.
Our protagonist, "Judar Schwarka," is one such slave that's been sold to Grasesta due to being captured after a lost battle. To win back his freedom, he will have to step foot into the twisted landscape of the Blockaded Expanse...

[Translated from the official website]