But a Side Character...or not? (Moved to new link)
Monetization/Continuation:
https://www.webnovel.com/book/not-the-heroine-not-the-villainess-but-a-side-character...-or-not_20990881406794305
Reiré Norman remembered her past life as an eighteen-year-old high school girl. Having these new memories she realized that she was reincarnated into the world of her most favorite light novel, Fight for Love and Acceptance. As a character that never appeared in the novel, she has given up on seeing the story events, that was until fate had something else in store for her. Now thrown into the story’s set environment, Roseward Academy, she had decided to interfere with the plot and save a certain someone from her impending doom. “Why?” you ask. Well, Reiré was a sucker for the tsundere villainess.
Promo/trailer: https://youtube.com/watch?v=UOQxUOC7MJ8