The Demon Ororon

The Demon Ororon (悪魔のオロロン, Akuma no Ororon) is a manga series written by Hakase Mizuki. The manga is licensed in North America by Tokyopop. The epilogue to the series, Empire of Midnight (真夜中の帝国, Mayonaka no Teikoku) has six chapters released as of 2007.

Plot
When Chiaki meets a wounded young man on the street and offers to take him in, she has no idea that she's just invited the King of Hell to move in with her. Out of gratitude for helping him, Ororon offers to grant Chiaki one wish. Chiaki, who lives a very lonely life, asks Ororon to stay with her forever. Remarking that "forever" is not the same for each of them, Ororon agrees, and the two of them quickly become attached to each other. Unfortunately, Chiaki soon realizes that falling in love with a demon has consequences. Ororon has abandoned his throne, causing renegade demons, bounty hunters, and his own brothers to come after him to take his crown. As Ororon fights to stay alive and protect the girl he loves, Chiaki is appalled by the violence surrounding her, and condemns Ororon as a murderer. Their relationship remains strained throughout the series as Ororon attempts to refrain from killing for Chiaki's sake, leaving himself open for attack in the process. However, when her friends are threatened Chiaki herself displays a horrifying power. The powers her angelic father sealed within her level an entire city during a battle with several bounty hunters, and Chiaki spends the rest of the series in agony over her hatred of what she and Ororon must do to survive.