Story: The Heroine's Best Friend was a Villainess

"Where the heck am I!!??" You looked in the mirror and you saw a girl who was 6 years old. You, A demon slayer who is respected a lot. You love using poison which is why you were known as the Venom Hashira along with your twin sister who is the Insect Hashira.

From a wealthy family, you were born in, but you were born but always arrogant as a child. A complete disappointment to your parents and in the end, death was your only answer.

"You're always my best friend" - Ariana, the heroine of the story.

How will you survive in this challenging world now? Will your fighting skills come to use? Will your medical techniques come to use? Now that you are in a new world, what will you do? Will you try to go back?