Yu Yu Hakusho: Ghostfiles

Yuusuke Urameshi is a violent, troublemaking 14-year-old who regularly skips school and gets into fights. His life changes when he unexpectedly sacrifices himself to save a child, leaving the afterlife unprepared for his arrival. With no assigned place among the dead, Yusuke becomes a ghost and must earn a return to life. He later works under Koenma, confronting demons that threaten humans through theft, dangerous weapons, and other attacks. His missions bring together an unlikely group that includes his rival Kazuma Kuwabara and the demons Kurama and Hiei.