The Kurogane House appeared in several manga by Go Nagai, all of which included Tsubasa Nishikiori. When Tsubasa took control of the inn, she would assist the protagonist in some way through the house's elite staff.
The Kurogane House is at first glance a standard Japanese-styled inn with rooms decorated with tatami floors, futons, and meals delivered on small trays. There are also hot springs for guests to relax in for both men and women. Beneath the exterior is a hidden hangar that stores the Hover Pilder and weapons made or used with Super Alloy Z and Photonic Energy. The hangar also has a chemical lab used by Tsubasa.
Most staff in the Kurogane House are dressed in traditional Japanese kimono and provide service to their guests when needed. Despite their appearances, some are also combatants who prepare for most circumstances. The strongest fighters among the staff however are the Kurogane 5, personally handpicked by Tsubasa.