This is the story of a 14 year old boy, Daisuke Niwa, who turns into Phantom Thief Dark when he becomes enamored with a certian local girl that he is fond of.  Poor little Daisuke is sucked into this tale of thieving, and the only thing that will return his life to normal is to steal the heart of the woman he loves.  Too bad that the object of his affections only has eyes for his other, more dangerous self!  Daisuke, or as his alter-ego, Dark steals artwork that have some sort of cursed power and cause troubles for the town and its people.  Once the works of the art are obtained, their power is sealed by him or his family (Daisuke's grandfather and mother).