Hyper Combat Unit Dangaioh (1987)

Mia Alice wakes up in a spaceship with no recollection of her past. Along with other three teens she was turned into an ESPer cyborg, set to be the strongest combat machines and sold as mercenaries for the space pirate fleet Bunker. But as they recover their memories, the four teens are against becoming slaves and now must fight for their lives by combining their powers into the mecha Dangaioh.