The Yamaguchi Residence is a historic two-story building with 15 rooms located in Sakai Ward, Sakai City, Osaka Prefecture, designated as an Important Cultural Property of Japan in 1966. Since 2009, it has been open to the public as part of the Sakai City Machiya History Museum. The residence is one of the few surviving early Edo-period townhouses, built shortly after the city center was completely destroyed by fire during the Summer Siege of Osaka in 1615. It conveys the atmosphere of traditional Sakai townhouse life to the present day. The property underwent several expansions and renovations from the mid to late Edo period. In 1775, the main house was renovated and an entrance, reception rooms, and a west storehouse were added on the south side; in 1800, a north storehouse was added, completing the current layout. Inside, visitors can see a large earthen-floored space with a kamado stove, wooden-floored living areas used for everyday life, and formal rooms and a tea room used for hospitality. The main house also introduces traditional local industries such as cutlery, incense, and dantsu (woven carpets). The garden on the north side features a large wax tree nearly 200 years old, viewable from the main house. Visitors can also enjoy guidance from volunteer tourism guides.