Once upon a time, there was a sad love that would never be requited.
But that alone does not give birth to a story. The man charged with the task of spinning this tale of love was no longer of this world.
The story lives on with the love forever immersed in sorrow.
Having lost its storyteller, the story is now wandering in search of its conclusion...
Chekhov's Gun: Towards the beginning, it's established that for all her talent and skill at dancing, Rue has difficulty mastering the basic endurance exercises. This later becomes her downfall when she loses in a dance off to the ghost.
Mythology Gag: The ghost challenging Rue (and later Princess Tutu) to a dance-off to see who can last longer alludes to the story of "Giselle", who became a willie. In the story, willies are ghosts of girls who loved to dance and have their hearts broken, and anyone unlucky enough to meet them is forced to dance until they die of exhaustion, much like Rue's dance with the spirit girl.
Our Ghosts Are Different: The ghost of this story is not only the spirit of a girl who never knew love, but is kept in the mortal planes by the heart shard of sorrow.
