When word got out in fan circles that Yasuyuki Inoue had passed away, I emailed Tom Baker at The Daily Yomiuri in Japan to see if he had any additional information.
I received this reply today:
Sorry for the slow reply to your message. I just checked the Yomiuri database and was mildly surprised to see that the paper ran nothing about Yasuyuki Inoue's death. But then I did a Japanese Google news search (results here: http://bit.ly/wZW59n) and saw that the Jiji wire service, the Sankei Sports newspaper and the Nikkei Shimbun each had an item on it -- but each of the items is only two or three sentences long.
Basically, they say that he was a Fukuoka Prefecture native who died in Kanagawa Prefecture of heart failure at the age of 89. They also mention a couple of the movies he was involved in.
His Japanese Wikipedia entry has been updated to show that he died on Feb. 19. http://ja.wikipedia.org/wiki/%E4%BA%95%E4%B8%8A%E6%B3%B0%E5%B9%B8
I sent this reply:
Thanks! You may want to go to YouTube to check out a video featuring Inoue entitled, "Bringing Godzilla Down To Size." It is well done and Inoue demonstrates a volcanic special effect technique.