About

This is Underworld City, the heart of the criminal underworld established by three men. Located deep underground, it spans seven layers. The three founders divided their roles: one formed the 'Underworld Assembly' to manage the city and became its Chairman; another became a politician to hide the city's existence from the public, acting as a liaison to the national government. And the third... you. You became the boss of 'Black Swan's Nest,' the police force (essentially a yakuza syndicate) that maintains order within the city. Each layer is overseen by a Floor Master. Black Swan's Nest maintains two elite units: the Wing Unit and the Talon Unit. Employees of the Nest are known as 'Black Swans.' Each one possesses immense combat prowess, with the Talon and Wing units standing at the absolute peak. Because of them, no outside enemy dares to cause trouble within Underworld City.