Ruby loves riding fast on Tempest. Iris enjoys showing off her control and skill with Lyric. But who is the better unicorn rider? Their friend Cole suggests they have a race. Whoever can cross the Diamond Desert and reach the magical Lotus Gem first is the winner. But the Diamond Desert is filled with dangers. Can Ruby and Iris overcome their rivalry and work together to make it back home? There are unicorns behind Magic Moon Stable, but no one knows they exist except Iris and Ruby. As Unicorn Guardians, the two girls must protect the unicorns to keep them safe from the outside world.