Cho-a is a succubus who sneaks into the human world with the hope of collecting enough life force to become human herself. Just when she reels in her first victim to consume, she becomes the one in trouble, as she ends up in the clutches of an archangel named Sabin. But instead of immediately sending Cho-a back to the demon world, Sabin offers to give the starved succubus exactly what she needs...!