Divine Interference (KNYxModern!F!reader)

When a normal, or so she claims, sadistic yet kind 19 year old girl gets stabbed to death by her enemy in front of her best friend, she is brought to another world in the body of her 10 year old self.

Y/N was never one to go out of her way to do anything unless it was to punish a pervert/bully for their misdeeds or to comfort one who is in pain, all she wants in life is to have fun and be in interesting and entertaining situations. So after the only reasons of her living, her best friends, manga, and anime's, were now gone, why should she want to live again, let alone in another world where technology doesn't exist?
Is what she thought, till she found out she was reincarnated into her childhood favorite manga.
Now, where would be more exciting than where the main character is? After all, everything entertaining happens around them don't they?

After taking a years to find the mountain the Kamado family lives, she gets taken in by them. During her stay, she continuously leaves to go on secret missions, visiting some people, while learning a secret brethaing style as a member of demon slayer corps. She was content with her life, not the most exciting but it was fun, especially after meeting a nice person who caught her attention. Now after years of staying in this world, she starts to forget the storyline, being entrapped by the happiness and peace of her life, until the day of tragedy struck when she saw her fiancé and Kamado family dead. Now she sets out for revenge and more fun with Tanjiro and his sister, and captures the heart of many

Y/N has always had this voice in the back of her mind. It only speaks when it matters. Never repeats and never more than needed to get the message across. Who is this voice? Why does it know so much? She doesn't know. Why does it know the future? How does it even know so much? She doesn't know. And why is it that every time she listens to it.. Things turn out in her favor?

Maybe she'll never know..

Or will she..?