Yiyun You was originally a happy little girl, until a disaster took away her parents, and she seemed to be the only one in the world. She still resented her parents for leaving her alone in this world. It wasn't until Yi Yunyou met Yu Kening that she discovered that there were people like her in the world. Later, they fought side by side and fought their way through the apocalypse.
Intention: In the end of the world, you are the only one