The setting is in Tokyo where most of the battling takes place. It is basically a robots (or Jaegers as they call them in this movie) versus aliens (kaiju). The Jaegers are controlled by humans inside of the Jaegers. Like a car, they have controls, but the Jaegers are controlled by 2 people, one for the left half and one for the right half. For better control, they have a "special connection" to the robot.
The Jaegers are the only hope for mankind against the Kaiju. The big Jeagers aren't enough to stop the Kaiju though. Everyone in the movie is racking their brains on how to stop the fearless Kaiju. Mankind is on the edge of being wiped out. What will the protagonist and group of friends do to stop the Kaiju?