After a meteor shower hostile giant insects appear in Japan and quickly begin multiplying and killing people. The Legion itself is an imposing monster that does impress.
Gamera appears and tries to fight Legion, but is quickly dispatched by the hordes of flying monsters it dispatches. It does take Gamera a long time to recover, but recover he does and again the battle for Earth is on.
The effects are top notch and the monsters are very goo indeed. There are plenty of scenes involving the insect monsters running thru Japan and killing people, and some of those are downright eerie. This film will please monster movie fans.