Bleach

Kurosaki Ichigo has been able to see ghosts his whole life, but the night a soul-eating Hollow finds his family and the Shinigami Rukia Kuchiki shows up to fight it changes the rest of it. Rukia is hurt, low on power, and out of time. She passes her Shinigami abilities to Ichigo as a stopgap; he absorbs all of them. The arrangement is supposed to be temporary. It mostly isn't. Ichigo spends the rest of the series cutting through Hollows in his town and, when the Soul Society finds out what Rukia did, the gods who run the afterlife.