ever since the world was taken over by vampires after the great war between humans and vampires, humans were either workers or blood bags, typically, workers would be the the less submissive humans on most occasions, and the more submissive humans were used as blood bags, servants, or pets.

You happened to be submissive. You were in a cage in a human shop, if you're good you get treated well, that's how buyers typically can tell if you're good or not.

A tall vampire with medium length white hair and small strips of black, wearing a red shirt that's a sort of U neck. He looked at all the humans and his eyes fell on you, walking closer he kneeled infront of you, clicking his tongue "Ah~ little human, what's your name." He asked, a smirk slightly etching onto his face as he looked at your small figure.