V--V G-----------PG----------PG13-----------R------NC17Why: v, al, n
"For the world in hollow and I have touched the sky"It is also apparently occupied by subterranean humans who would very much like to move "upstairs".
Flash back to 1945 in the Pacific Ocean. Two massive ships stream towards each other, one is controlled by Imperial Japan and carries an oddly dressed young girl named Annette. The other is controlled by the United States and carries another young girl named Avatar.
These two massive, and rather otherworldly ships, are poised for battle. The Japanese ship gets a communication stating that Hiroshima had just been destroyed by an atomic bomb. A bit after this, the U.S. ship fires upon the Japanese ship. This ends the first and only wartime use of the Ra ships.
Go forward to now.....
A massive cylinder appears over the south pole and begins to melt the ice cap. All reasonable attempts to destroy the cylinder fail. In addition, gravity lenses begin to appear. These large round objects focus and redirect energy beams that the massive cylinder begins to fire at the U.N. forces.
When all looks lost, the Imperial Japanese Ra ship appears again, after more then 40 years, and proves to be an effective defense for all of mankind that lives on the surface of the Earth.
Avatar's plans to destroy the surface humans, however, proceed with the construction of a Megaring which begins to circle the Earth. Upon completion, the ring would rain microwave death down onto the surface of the Earth.
Super Atragon is a fairly decent anime series with pretty nice animation.