Genshin Impact, I, a weak person, am challenging myself to find a solution that will bring me lifelo

An unknown girl in a wheelchair with a serious illness made a deal with the devil one day.
As long as you become a precious childhood memory for others and make them regret it for the rest of their lives, you can get a healthy body and a chance to start your life over again.
But this requires her to successfully perform seven times. Every time she fails, her body will become worse. Faced with this only chance, she chooses to accept the devil's request.
——So many years later.
Whenever they grow up and reminisce, they always think of their childhood sweetheart who passed through their lives like a shooting star when they were young.
In Mondstadt, she is the "wheelchair sister" that the Wave Knight loves the most.
In Liyue, she is the “insignificant” person that Zombie Qiqi is most reluctant to forget.
Inazuma, she is the Summer Festival Queen's closest and best friend who watches the fireworks together.
In Xumi, she is...
(A reminder before watching: her identity will change in each volume. She may meet someone by chance, but she will not seek out her confidante or start a harem. The story of each volume is the end of a period of her life and the beginning of another journey.)