Maybe it's just me but this one seems to have totally slipped under the radar.
I found this film while scouring Netflix. Apparently it is a German television documentary revolving around monster films. Teruyoshi Nakano and Kenpachiro Satsuma are interviewed and apparently dives a great deal into the genre. I tried looking for some more information but there is not much out there except for what I found on IMDB and other places.
http://www.imdb.com/title/tt1305723/
http://www.japanvisitor.com/index.php?cID=367&pID=2131