Starlight Sapphire is a private in Celestia's royal guard. When the princess is attacked, she makes Starlight her personal guard. With her sister banished to the moon for 1000 years, she's lonely, and needs somepony to talk to. It starts with a simple crush, but they soon start to develop true feelings for one another.

Meanwhile, a sinister plot to usurp the throne is unfolding, and the princess is in great danger. Will Starlight be able to save the one she loves, or will Equestria fall to its enemies?