The Earth has a defense system against large meteorites that are in collision course to it. This protection system has the Comet Blasters based in space stations as a 1st line of defense, using nuclear warheads launched by spaceships. The 2nd line of defense are the Meteor Sweepers based on ground airbases using hypersonic planes with special missiles to deal with the resulting debris from the 1st blasts. Mikaze is a troubled girl that is a trainee pilot for Meteor Sweeper team that dreams to become a prestigious Comet Blaster pilot. Stratos 4 turns around Mikaze�s and her teammates� challenge to become real pilots, while the Earth faces its threats that comes from outer space.