In researching Godzilla, I learned about Manda and the Atragon in the film "Atragon." I watched it and wanting to learn about it, I came across "Super Atragon." I saw that both were based on a book called "Kaitei Gunkan" by Shunno Oshikawa. If you would like a summary on "Atragon" you can go right our own section here http://www.kaijuphile.com/rodansroos.../atragon.shtml
For further information go to Toho Kingdom's section here
For Super Atragon go here
There are several differences between the two films such as the Captain's long lost child is a son instead of a daughter or that in "Super Atragon" the battle is taken to the Antarctic and later the sub's base while in "Atragon" the Captain takes it straight to the bad guys.
The two biggest difference are Manda and the villains. In Atragon, Manda is the serpent god of the Mu Empire and protects his worshippers. His worsippers are the people of the Mu Empire who seek to reconquer the surface world. It begins in the last days of World War II when Captain Jinguchi of the Imperial Japanese Navy is lost for fifteen years but spends that time secretly building a submarine he'd designed... and which the Muvians worry about.
In "Super Atragon," there is no Manda. Also, the "subteraneans" send America and Japan advanced technology in 1932 to test them. If they use the technology for peaceful purposes, the surface worlders will be left alone but if they use it for war, they will have proven their evil. In that last days of World War II, America builds the Liberty and Japan builds the Ra which destroy each other. In the present, Anne--who'd seen WWII Japan--who thinks that humans are good
and Avatar--who'd seen WWII USA--who thinks that humans are bad
awaken and continue their duel to see whether or not mankind will live.
If you have seen these Toho films and would like to comment on them, please do so. Also, if you have read the original book on which they were based, "Kaitei Gunkan" by Shunno Oshikawa, or know anything about it please leave a comment.
Thank you and have a nice day!