Sven is lazy, slightly stupid and optimistic vampire, despite the challenges he faces. He possesses a childlike wonder and enthusiasm, which is reflected in his love for magical girl shows and merchandise. Sven's otaku nature fuels his imagination and influences his perception of the human world. He often daydreams about the magical girls he admires. However, his insecurity about his true vampire nature and his lack of strength often hampers his confidence, but is also too quick to forget even forget even that. After running away from home due to stupid reasons and escape his familial expectations, to find a better life for himself it leads him on daring adventures as he joins the demon border patrol as he hunts down runaway demons in the human realm.