The Demon's Daughter is Curenatsuki's fifth fan series on this wiki.
Every century, there is an unlucky girl who is possessed by the evil demon called "The Demon's Daughter". The people close to this girl will get attacked by "The Demon's Daughter" and slowly die. The only people who can stop "The Demon's Daughter" are girls who choose to fuse with an angel and battle for the world's safety called "Sugar Angels".
The Demon's Daughter of the 21st century happens to be a girl from a rich family, Eri Tachibana. On her 14th birthday, the demon awoke inside Eri and killed her maids and servants. Her twin sister, Ai Tachibana, saw all this behind a pole. She called out to Eri, but Eri advanced on her and tried to kill her. Ai, out of fright and sadness, ran out of the house and to her best friend Natsuki Akimoto's house. Natsuki and her parents explained about The Demon's Daughter and suggested Ai to be a Sugar Angel along with Natsuki. And now, Ai and Natsuki must battle Eri for the world's safety. But will Ai be able to fight her own twin sister...?