The National Museum of Japanese History -- Kokuritu Rekishi Minzoku Hakubutsukan (Rekihaku) / Sakura city Chiba pref.
To tell the truth, I had not expected that museum so much until I went in. I had thought of it as a one of a local historical museum.
As soon as we went in, I realized that I was wrong. It was amazing. It was worth seeing. It included plenty of valuable exhibits and that displays were marvelous. I was excited and enjoyed it very much.
While I was glued to the exhibits, my cousin, a reseacher of here, had been kindly guiding my daughter for 3hrs! Thank you very much!
According to the website, the audio explanation equipment for foreigners seems to be borrowed at the information desk.
The National Museum of Japanese History is located close to the Keisei-Sakura station of Keisei line, or the Sakura station of JR Sobu line. You can get the museum by bus from both stations. (English official site)