Dungeon ni Deai wo Motomeru no wa Machigatteiru Darou ka: Familia Chronicle

For the skilled former adventurer Ryu, it's another eventful day at the Benevolent Mistress! A certain couple's only daughter has been kidnapped, bringing Ryu out into the streets to search for her, in the name of justice and Astrea. Her investigation of the missing child eventually leads her to a lawless area of the Labyrinth City, the Grand Casino, where money and power decide everything! This is the start of the Gale Wind's tale in the city of Orario, home of the Dungeon and adventure! (Source: Yen Press)