*Our children have spent their adolescence in piles of exercise books.
Our children have spent their years doing exercises one by one.
So a certain god became lonely and wanted to create an exercise book by himself...
So... The heroine is the candidate for that exercise book...
This is how the tragic journey unfolds...*
P. S.
My writing style is very poor... Be careful...
Not a Mary Sue. It may be a little bit silly, so I'll try my best to change the heroine's character...