The Needless are mortals that have restricted a "disease," as people label it, which permits them to use unusual powers.
The opening theme is "Modern Strange Cowboy" by GRANRODEO and the ending is "Aggressive Zone" by Needless Girls, composed of the female seiyuu of the series, Aya Endo, Yui Makino, Emiri Katou, Saori Gotou and Eri Kitamura. The second opening is "Scarlet Bomb!" by Aki Misato and the second ending is "WANTED! for the love" by Needless Girls.