Xiyue is a black cat, to be precise, a cat demon. When he was facing drowning, he was rescued by Rintaro, who loved exploring. He agreed to protect Rintaro's daughter Ema as repayment, and was sent to the three-year-old Ema. Rintaro disappeared again, and from then on, Xiyue lived a life of being both a father and a mother.
When Rintaro appeared again, he told Ema and Xiyue that he was getting married and asked them to live in the home of his remarried partner who had thirteen sons.
Originally, Xiyue thought that since someone could take care of Ema, she would go directly with Ema in the form of a cat, but she was shattered by the pitiful offensive of Zhu Li and Ema. She really couldn't stand Zhu Li's thoughts and Rintaro's instructions, so she had no choice but to use human form and Julie to guard against those thirteen brothers who were said to be "perverts".
But who will tell her why she just wanted to protect Ema and guard against "perverts", but those "perverts" came over! Don't you know that transvestites have different paths? ?