This building was constructed in 1921 as a reception and accommodation facility of Mitsui & Co., Ltd., Japan's first general trading company.

The style of half-timbered wooden architecture has been adopted for this building, with wooden pillars and beams exposed.

Each room has a fireplace and mantelpiece, and door and window frames are decorated in the art-deco style.

The building is famous for Albert Einstein's praise of its beauty when he stayed there during his visit to Japan in 1922.

It houses a restaurant and a hall on the first floor, and the Einstein Memorial Room and an exhibition room focusing on Hayashi Fumiko, a famous Japanese female writer.