Read it official: VIZ or MANGA Plus. Chapter 23 names the architecture the rest of the auction is about. The Storehouse (蔵, Kura) is a subspace. Kyora stores loot and people in it. Hakuri will inherit it. Chihiro later surrenders Enten on purpose so the seventh blade can scout the Kura on its own charge.
Why the title is a place
Early chapters are objects and meals. The auction speaks in rooms. Storehouse is the first room that is also a weapon. Dual inheritance, Isou plus Kura, is historically almost unique in the clan. Hakuri is still the discarded son in this issue. The architecture is already waiting.
Longer file: the Storehouse. Clan: Sazanami. Arc: Rakuzaichi. Registration as a technique: Sazanami registration.