yu yu hakusho
A manga series written and drawn by Togashi Yoshihiro, later adapted into an anime series. The manga ran from 1990 to 1994 from Weekly Shounen Jump and the anime from 1992 to 1995.
Teenage delinquent Urameshi Yusuke surprised the Underworld when, in an uncharacteristic act of altruism, he was killed saving a boy from a speeding car. With no place prepared for him in either Heaven or Hell, Yuusuke was returned to the living world, but not before he was recruited by Koenma, son of the ruler of the Underworld, to become Spirit Detective, charged with investigating supernatural activity in the human world.