It's probably the drama version, but a lot of things were deleted to make it closer to the anime. Original heroine! Can be replaced or knocked √ooc warning! As for the introduction, I'll leave it blank for the time being. They are childhood sweethearts + senior brothers and sisters. Demining: There are some abuse points. The author is not friendly to the protagonist group in the drama version, but he won't write too much about it.
Purpose: On love under the relationship between fate and causality