You're My Brother and I'm You're Princess

This is a Kuroshitsuji fanfic.
Celestia is alone, more alone than she's ever been.
She's the Queen's daughter, though she's never been shown to the public.
Most of the servants think she's a myth.
High ranked servants aren't aloud to speak of her.
She's never been aloud to have a suitor and her mother is strict with everything.
What if a boy and his butler that have 'killed' the Queen...
Find this one girl?

A world of adventure she's only seen in books will finally come to life.