Gokaiger is the code name given by members of the crews of the USS Yagami and SS Ponyo for a collection of five energy traces discovered in and around the Sol System, in the dimension encountered by the Yagami in 2380.
These traces belonged to a group of warriors known as Kaizoku Sentai Gokaiger, who defended a still-different dimension than the one the crew of the Ponyo inhabited. (Team Chipmunk: The Next Generation vs. Star Trek: Omega Force)