This show provides examples of:
- Boy Meets Ghoul: There's Kumiko herself, and then there's his dead cousin who's returned as a Cute Ghost Girl to make him fulfill his promise to her.
- Horny Devils: All demons have bat wings and horns. The concept of a succubus is an invention by sexually frustrated monks though. They really just eat your soul.
- However, Kumiko decides on a whim to indulge Ken's last request and finds that she is a Horny Devil for him.
- Our Angels Are Different: They're reincarnated ghosts and have very human emotions.
- Supernaturally Delicious and Nutritious: This is Kumiko's excuse for why she doesn't eat Ken's soul all at once, a transparent excuse for hanging around to enjoy sex with him.
- Tsundere: Ken winds up with two of these after him, a judoka and a biker girl, both of whom are convinced that Ken is the only person who can see past their tough exteriors.
- Those Wacky Nazis: It's rumored that Dr. Josef Strauss was one of these. He's actually a Fallen Angel.