Those who live in the world of day under the illumination of the sun are known as humans, while those who rule the world of night under the cloak of shadow are known as vampires. Each race while in seeming opposition to one another, in truth, rely on each other for survival as vampires leech blood off the humans for sustinance and humans rely on the strength received from them to live on the barren land that continues to erode away at the remnants of a once pristine landscape.

Follow the adventure of Touma, last child to the human race, who finds himself caught in the middle of a world ever divided by growing light and darkness soon after his arrival in the creepy and haunted town of Casketville. In a fated encounter with a beautiful vampiress named Stella, the two find themselves undergoing certain physical changes they must counteract while hiding the truth from those around them if they hope to survive!