Blood Lad follows Staz, a vampire that is obsessed with the human world, and Fuyumi, a human girl that was killed and turned into a ghost after wandering into the demon world. Staz promises to help Fuyumi regain her humanity by bringing her back to life, as it means that he would be able to visit the human world
Takato Matsuda, Ruki Matsuno, and Lee Jenrya are children who have, by fate, recieved real Digimon, unlike the imaginary ones in the card game they play. Each of the children, or "Digimon Tamers", have their different views on how Digimon should be treated. But when other Digimon begin to appear around Japan, they must put aside their differences to fend off the digital intruders; even though Yamaki, who is the head of a secret organization called Hypnos is trying to eliminate all of the Digimon himself.
In another dimension the Devil King Sadao is only one step away from conquering the world when he is beaten by Hero Emilia and forced to drift to the other world: modern-day Tokyo. As "conquering the world" are the only skills the Devil King possesses - and are obviously unnecessary in his new situation - he must work as a freeter to pay for his living expenses.