Based on the celestial's decree, four palaces were set up in name of the Four Auspicious Beasts*. They then instructed humans to rear animals in each palace. Though this role was deemed to be the lowliest job in the palace, to Yu who is an animal lover, being able to eat high class leftovers while taking care of animals was like heaven. With her cheerfulness and vast knowledge of animals, she solves the  palace's problems one after another. Then one day, she is assigned to take care of a terrifying divine beast...

*from Chinese myth. Also known as the Four Symbols.