This storehouse is one of the few buildings remaining of a large compound belonging to a feudal lord centuries ago. This 9 x 25 meter stone storehouse may be large, but it was a relatively small part of the total compound. It was used to store stocks of grains that had been paid as taxes to the lord's fief. One of those grains, rice, was commonly used as currency well into the Edo period (1603-1867), and as such, this building was something between a grain warehouse and a bank vault.
To preserve the stocks of rice and other grains, the storehouse was built from basalt, a type of volcanic rock found in almost all of the Tomie area. Large slabs of basalt were hewn, chiseled, and carefully shaped into building blocks. No mortar was used to hold the blocks together. This style of precisely fitted stonework was a very laborious and expensive construction technique and was normally used only for the storage of very important grains.