The Young Master and the Lonely Cat

This is a story of love. An uncut ruby and a polisher. A man and a cat. A man whose job is to weed out the traitors and take care of them. A lonely girl who spends her days in a box at the back of a dark alley. She meets a mysterious man, whose eyes express pain and fatigue. He turns to her and says, "do you want to leave that box?" He extends his hand.
The girl stares into his eyes, searching for deceit. Finding nothing, she takes his hand, "I wish to go where you go."
The man smiles gently, his cold eyes twinkling. "Then become my partner."
Pricking her index finger with her sharp canines, she offers her blood to the man. He returns the gesture by pricking his own finger and the two write a special symbol upon their hands in their blood. The contract is done, their fates sealed.