A motion sensor activated sliding steel door in Kohime's room leads to an armory lined with weapon racks, trunks, and mannequins - if it's a weapon or armour, it can be stored somewhere here, and the amount of storage space available allows one to store enough to arm a small army. In addition, a table in the center has a map of Tokyo-F, on which erasable lines can be drawn by tracing a finger along its surface. For, you know, completely innocuous planning.