Tensei Akujo no Kuro Rekishi

As a teenager, Konoha Satou filled notebooks with an extravagant fantasy romance that placed an idealized version of herself at its center. Years later, those writings have become the kind of embarrassing past she would rather bury forever. After a sudden accident, however, Konoha awakens inside that very story, not as its beloved heroine but as Iana Magnolia, the hateful villainess she personally condemned to a string of disastrous endings.

Remembering the plot gives Konoha a chance to dodge the death flags she once wrote, but survival also means confronting every melodramatic detail of her old imagination. Then Yomi appears, a mysterious man she cannot remember creating at all. If characters can exist outside the script she knows, Konoha's supposedly perfect knowledge of this world may no longer be enough to keep Iana alive.