It is sometime in the future, where a certain European city extends far underground, even secret, dark levels that have the key to the past. Ex-assassin Mihai has returned and is living with Kiri, who now runs a resturaunt. Sword-wielding Naota, Haine, a mysterious product of genetic engineering and his sometime partner Badou (whitehair and eyepatch), not to mention the scary but cute twins Luki and Noki, hang around plying their dangerous, and often deadly trades.