From a world, parallel to the normal human world, females known as "Jūden-chan" (charger girls) are patrolling the human world in search for individuals who feel depressed and unlucky. These people are ranked from A to F, F being normal and A being near suicidal. When the Jūden-chan find targets ranked C or higher, they charge these people up with the help of electricity in order to improve their mental states. Whilst normally unseen by human eyes, one of these Jūden-chan, Plug Cryostat, accidentally meets a young man who is able to see her, because she was targeting his sister (his father in the manga). This series revolves around the various antics between the main characters and the quest for this Jūden-chan to improve herself.