On Mid-Autumn night, Yao Jianing spends the entire day preparing twenty dishes, hoping only to return to her parents' home and share a mooncake with her sick mother. But her husband's family hides the keys and locks the front door. When Grandma declares, "Once you've married into the Cheng family, you must follow the rules," her husband, Cheng Yuanzhou, smashes the door on the spot to protect his wife. Yet what he breaks open is not just a door, but also the lives of three generations of women in the Cheng family, bent under the weight of old-fashioned rules.