Tired of being beaten by Mario, Bowser travels to a new world to conquer it instead and takes Princess Peach with him.

Of course, Mario and Luigi immediately follow him to this strange land of Equestria, where they learn that it has heroes of their own and a slew of Power Stars scattered by the Koopa King.

The ponies, joined by the Mario Bros must find the Power Stars before Bowser and his army. But before they can, Mario must first find his allies lost within Equestria.

And who is that mysterious hooded pony that keeps coming to Mario about stopping a greater evil?