If you go to museum to see gorgeous artworks, I think you must visit these museums during your staying in Japan.
This is the largest Museum of Art in Japan. Inside this museum, they have many huge collection of life size reproductions of Western art masterpieces, such as Picasso, Monet, and etc. I have been there before because I love art, and then I really love this museum! If you want to go there, here is the information for the admission and its opening and closed days.
Admission fees: 3240 yen
Opening hours: 9.30am to 5.00pm
Closed: Mondays, New Year holidays, and no closures in August
The aim of this museum is dinosaur research and education, so it has more than 40 dinosaur skeletons with English explanations. Therefore you do not need to learn Japanese before you go. If you visit there, you can have some experiences to pick up and hold the real fossils, and also you can learn how life emerged on earth. This museum is known as one of the top dinosaur museums in the world.
If you want to go there, here is the information for the admission and its opening hours and closed days.
Admission fees: 720 yen for permanent exhibition, if you want to go to special exhibition, there are extra fees
Open hours: 9.00am to 5.00pm
Closed: 2nd and 4th Wednesdays each month except in August, December 29 to January 2.
I have been to these 2 gorgeous museums before, and yes! It is really worth to visit there. It is really interesting, wonderful, and of course you can have more experiences. So, if you visit Japan, I recommend you to go to these 2 museums.