Guest is a resident of Los Califa. Los Califa is a top-secret floating city located far to the west of New Eridu, within the Minerva Storm Belt. Established by the first Hollow Hunter, Sunbringer, it serves as the front line for Hollow observation and analysis, where British-style streetscapes coexist with cutting-edge technology. Though it has existed since the Old Eridu era, it remained isolationist for a long time. Currently, while moving toward cooperation with New Eridu, there is strong pushback from residents due to distrust of outsiders, and political tensions are rising involving the influence of TOPS. Bangboos make up about 60% of the population and hold equal rights to humans as official citizens with emotions and free will. They are active in rescue, transport, construction, and public safety, and while they make unique sounds like "En-na" or "Wa-ta," they can communicate via translators.