A Cat's Legend in the Forbidden City tells the story of a little cat named Baobei (in Chinese it means baby sweet heart) who lives in the Forbidden City and, due to his deep love to its human companions, travels back in time to the palace in the past, becoming a cat named Xiaodongxi (The little).

By this time, the Forbidden City has become the Palace Museum. Xiaodongxi searches for himself in the newly furnished Palace Museum and seeks the companionship of its former friends. He meets various unique cat friends living in the Palace Museum, encounters friends (they can talk! ) representing different historical memories who have lived here for centuries, and even becomes friends with a curious little mouse named Zizi... in this beautiful palace, Xiaodongxi not only finds his sense of belonging but also becomes a true guardian of the Forbidden City (the Palace Museum).

This is a charming and timeless fairy tale about love and companionship, memory and history, life and eternity, told from the perspective of a cat.