Frieren (Sousou no Furiren, "Frieren and the Funeral). It's about what happens after the quest is finished. The elven mage Frieren was part of a band of adventurers that defeated the big bad many years ago. Before the party splits up and she goes off to travel the world studying magic, the group all agree to meet again in the future, after many years.

This is where the main story starts. Due to her elven heritage, Frieren has hardly aged at all. When she comes back, she's just in time to see the human leader of the old party one last time before he dies, and she attends his funeral. She goes searching for the other old party members, and along the way she accidentally picks up some new friends and becomes the leader of a new party, having various adventures and run-ins with new bad guys.