The Tomonotsu Merchant House, built in the late Edo period (1603–1868), is designated as an Important Cultural Property of Fukuyama City. The layout of the main building and the functional properties of its storehouse make it representative of the merchant houses that existed in Tomonoura during this time period.

The main building is wooden and consists of two floors. After entering its narrow frontage, there is a dirt-floored area, beyond which you will find a row of three rooms. This layout is typical of the traditional townhouses of Tomonoura.