Konoha Satou is the author of Dark Past, a romantic adventure-style fantasy novel she wrote in middle school about the life of Konoha, the daughter of a count who fell in love with her knight. One day, her mother found out about Dark Past, but as Konoha ran out of her house she got into a traffic accident and died!

When she opened her eyes, she found herself in the world of her own creation as Konoha younger sister, Iana, a character she created to be the greatest villainess of all time! Somehow, she been reborn as her sister?