In the nearly 80-hectare Koganei Park in the western Tokyo suburb of Koganei stands a house that once belonged to the 11th head of the famed Mitsui zaibatsu.

The home of Takakimi Mitsui (1895-1992), who is also known as Hachirouemon Mitsui, is one of 27 architectural gems in the park's Edo-Tokyo Open Air Architectural Museum.

The two-story house was built in 1952 on a 4,000-sq.-meter plot in the Nishi-Azabu district of Minato Ward, Tokyo. Mitsui's earlier residence was destroyed in an air raid in 1945. The house was moved to the open-air museum in 1996 after Mitsui's offspring donated it to the Tokyo Metropolitan Government when they gave away the Nishi-Azabu land to the tax authority as inheritance tax.