What are the rules for the mouse in the big fish begonia?

In "Big Fish Begonia", the rule of rat girl is: no love.

Rat girl committed forbidden love. The rat girl is a human being, and the spirit girl is "other people", which is why the soul of a bad person is sealed, and the soul of a good person can't leave for 800 years. ? After the appearance, the rat girl kept talking about the goodness of the world and said a sentence of music. The word music can't appear in the world of "others", so the word must come from this world. Rat girl has been talking about the beauty of this world and can only explain two possibilities. First, Rat Girl has been to the world. Second, the rat girl came from the world and was originally human. Moreover, the spirit woman is in charge of good people, the mouse woman is in charge of bad people, the spirit woman loves cats, and the mouse woman loves mice. The spirit girl said that she practiced for 800 years to atone, and the rat girl was later proved to be sealed. It can be speculated that the wizard may have committed forbidden love 800 years ago, such as the love between man and nature. After all, the voice advantage of Lingwu is more like a man. The spiritual woman helped Toona sinensis because of her pity, just like seeing herself in those days, fearless and willing to give everything.