This is the story of a 14-year-old juvenile delinquent who dies once, but is brought back to life to work as a sort of psychic detective/troubleshooter. As his "Ki" powers increase, he and his friends (who include 2 demons) run into more and more nasty-bads. Finally, they are challenged to a gigantic demonic competition, which unfortunately lasts a grand total of 7 books out of the entire series, though it supposedly lasts only about 10 days. They win, of course, but are immediately faced with the problem of Some (Powerful) Idiot opening a hole between the Real World and the Demonic Plane. After that, things rapidly wrap up.