Sigma, a man with no past, a member of the Decay of Angels—a widely known terrorist organization— and the general manager of a well-known casino—the Sky Casino (A straightforward name, it is quite literally a casino in the sky. It hovers over Yokohama). Sigma, although acting well-kept in front of customers and staff, shows that he has no actual confidence in his skills. He aims to find a place to call home, live a life where he doesn't feel manipulated.