The girl has lost a lot of memory. She does not remember everyone who once loved her, nor does she remember everyone she once loved. She only remembers that her name seems to be - Xuanyi, and she only has a first name and no surname.
Following the message "she" brought, she embarked on a journey to find the past, present and future.
She also once couldn't find the meaning of her existence and lost herself. Fortunately, she still had friends who could accompany her, and her brothers from another world, those who had given her different surnames, accompanied her to find the meaning of living.
This article is also called "Why am I still a sister" and "Why is my sister always wanting to commit suicide"