"Aku no Musume" is the first in the Story of Evil series. "Aku no Musume" tells of the basic story of the tyrannical rule of Riliane Lucifen d'Autriche. The man she loves is found to be in love with a woman from the green kingdom of Elphegort. She orders the razing of Elphegort, killing all women with green hair, and is subsequently overthrown for it and executed.
"Midori no Musume" is a fanmade story supposedly told by Miku. It states that Miku was secretly a princess who was told to seduce KAITO by her father and was instead in love with Len, but when Len arrived to kill her, she committed suicide instead and wished that Len could have been the one to do it. She reflects on the fact that her only purpose was to be a sacrifice to end the tyranny of the yellow kingdom, and that Len was the only one to bring her happiness. This plot has now been considered almost entirely moot; in the original story, Miku was hidden away in the kingdom's burn (proven by the novel and mothy's blog), killed by a stranger or someone she did not know, likely Len (proven by the novel and the small hint from Servant of Evil~velvet mix~), and was not a princess (proven by the novel, mothy's blog, "The Daughter of White", and "Tree Maiden ~Millenium Wiegenlied~").
"Fukushuu no Musume" is a fanmade story supposedly told by MEIKO. MEIKO, a village girl vowed revenge against Rin because Rin murdered her lover as well as deprived the rest of her family of food, and was hired by KAITO to begin the rebellion. Although she later found out that Rin and Len had switched, she did nothing about it. This plot has also been considered moot; in the original story, MEIKO wanted vengeance because Rin killed her father Leon, a guard (proven by mothy's blog and the novel).
"Yami no Ou" is a story not affiliated with the Story of Evil series; however, the song contains the same tune and background music as "Daughter of Evil". It details the story of how KAITO, a vampire being deprived of blood, chases after MEIKO, but is decried as a pervert and locked up in jail. He withers to death, forgetting that he has the ability to turn into mist. It has a comedic tone to it, unlike the other songs.
"Uso no Utahime" is a story not affiliated with the Evil series; however, the song contains the same tune and background music as "Daughter of Evil". It details the creation and planning behind the prank Vocaloid Kasane Teto.