Chang Er and Hou Yi got punished and were descended to the Earth from the Heaven by the Jade Emperor.

Hou Yi rarely stays at home because of his job, making Chang Er feels lonely and depressed, especially when she knows her husband is having an affair with the wife of God of Water, Feng Meng

Hou Yi realized his wrongdoings, and went home to his wife, Chang Er, and brought a pill to make them ascended back to the Heaven.

While Hou Yi was away, Chang Er got provoked to go to the Heaven by herself by Feng Meng, and she did. When Hou Yi went back to see Chang Er, he saw his wife ascending to the sky, and in this opportunity, Feng Meng ended up killing Hou Yi. Chang Er regretted her act and she got punished by the Heaven to go to the moon instead of Heaven because she neglected her husband, making her the Moon Goddess.