Plot

The demon's soul is the soul of  possessed Vampire.Vampires turn into demons if their body can't take human blood.They try to kill all of the population of humans to summon him, the Demon king, through an ancient process called the Demons Soul. They go to a masquerade ball to find out more about the the demons and steal the Demons Soul. The ball is at Julia’s old mansion. Takashima, is behind the opening of the Demon's soul trying to get Julia to marry him, to become the heir of all vampires.