I went to see this exhibit in March.
http://www.japantimes.co.jp/news/2013/04/04/national/minamata-exhibition-honors-doctor/
In addition to Dr. Harada’s role as a leading advocate and researcher here in Kumamoto, he was also very active internationally:
“While conducting research on mercury-poisoning victims in Brazil, Canada, China and other areas of the world, he also contacted those who suffered carbon monoxide intoxication following mine accidents in the 1960s, according to the exhibition.”
The exhibit is fairly small so I’m not sure I can recommend making a special trip to Minamata just to see it. On the other hand, if you are in or near the Minamata area, I recommend that you pop in to take a look at the photos.