Momo is a calico cat who usually just lazily basks in the sun, but unexpectedly turns into a human toddler, and is broadcasted live in front of audiences nationwide, exploding on hot searches. For the sake of her dried fish, Momo can only reluctantly sign a fake brother-sister agreement with her cat servant, playing an obedient and well-behaved younger sister, while figuring out a way to save the cat servant's life. However, this cat servant's life is even harder to save than the fish in the pond!