When a college student wakes up to find herself in the body of an otome game villainess, like most, her first thoughts pertain to ensuring she's able to live a full life and not die at the hands of the heroes. But instead of trying to make friends with the main character and love interests, she plots out a new plan: level up as quickly and efficiently as possible to give herself a better advantage!

Full review here:
https://yattatachi.com/villainess-level-99-i-may-be-the-hidden-boss-but-im-not-the-demon-lord-volume-1-manga-review