Born in an alternate timeline where the Earth is almost destroyed by two evil Jinzonigen. Trunks or Mirai Trunks (Future Trunks) was trained by the last surviving warrior, Son Gohan. After Gohan gets killed by the Jinzonigen in the Trunks Special, Trunks gets the anger he needed to transform into a Super Saiyajin. He is later sent back in time using his mother's time machine. There, he kills Freezer and Cold-sama and then warns Gokou of his disease and the fate of the world without him.

Instead of returning home right away, Trunks travels three years into the future: the day the Jinzonigens attack. Trunks brings the news that they're the wrong Jinzonigen. And then the real ones show up and whup ass.

While training in the room of Spirit and Time with his [alternate] father, he learns the ability to become Ultimate Super Saiyajin. Althouh he doesn't really get to use it until Perfect Cell nearly kills Vejita, Trunks makes another transformation. This form is a variation of USSJ, that makes him even more powerful, surpassing that of Vejita.

Later, when Cell returns from "death," he kills Mirai Trunks. After the long greuling battle with Cell, Trunks is wished back and then returns home to his timeline.

However, his presence in the past has not changed his future, it was already too late. The Cell of his timeline attacks almost as soon as he gets back, however, Trunks is way too powerful now and easily defeats him. This is the last of Mirai Trunks, never to be seen nor heard from again.