Love can strike when you least expect.
Sometimes it’s just when you see an old friend in a new light.
This is what happened to Princess Luna and Rarity, both of whom admired each other, but never in a romantic way.
All that was destined to change.
It was written in the stars.
Luna x Rarity

This can be read as a stand-alone story or continued to its sequel Luna's First True Love, when we find out about the mysterious pink unicorn in Luna's precious oil painting.

There is another sequel, A Hearth's Warming to Remember, that follows Luna and Rarity to their first Hearth's Warming together.