I am a foreign tourist and spent approximately 90 mins in the museum. I joined the guided tour hosted by 小柴-san and his explanation goes well with me, at the help of some online translation and the sign boards. He is very knowledgeable and it is a shame his English is not as good, but I enjoyed the tour. 
The souvenir shops sell a lot of unique items, however I find it a bit overpriced, even with a discount ticket.