In the past, the 34 Super Sentai defended the Earth against Space Empire Zangyakku. The soldiers of legend lost their powers during this battle, but through their sacrifice, Zangyakku was able to be repelled from the Earth.
Several years later, we meet a group of young pirates who travel aboard the ship, GoukaiGalleon. They are in search of the “Uchuu Saidai no Takara” (Greatest Treasure in the Universe). They head towards Earth, where it is said the Greatest Treasure rests.