Also known as 'You You', this is the palm-sized white rabbit who is the train spirit of a time-space Interdimensional Train. The original ticket holder died, so the train chose Sang Chu as the new service target. Tu You explained to Sang Chu that she must earn enough money within one month (later reduced to about twenty days after she was unconscious for ten) to buy the train ticket, otherwise she will be annihilated by the rules of time and space when forcibly brought back.
