Built in 1913 (Taisho 2) and used as a consulate until 1934, it was renovated in 1992 and opened to the public as the Port Opening Memorial Hall. The consular office and family room are reproductions of the rooms used by the third consul, Richard Eusden, and visitors can sit in the chairs and touch the furnishings (with some exceptions).

At the Port Opening Museum, visitors can learn about the history of the port from the arrival of Perry to its opening to the outside world through panels, and by looking through a wooden barrel scope placed in the room, they can enjoy watching the changing scenery of the town and videos of foreigners dancing to music in a unique way.

In the 2023 renovation, the tea room and store on the first floor will be redesigned, and a new "Princess Photo Space" will be set up on the first floor, complete with bright red chairs, robes, and a replica of the tiara actually used by Queen Elizabeth II, making it a photo opportunity. The rose garden in the courtyard, with 153 roses of 60 varieties (as of July, 2008), is usually in full bloom from late June to early August. It can be used without entering the Kaiko-Kinenkan.