In an alternate version of the present, Tokyo has been decimated by a shocking terrorist attack, and the only hint to the identity of the culprit is a bizarre video uploaded to the internet. The police, baffled by this cryptic clue, are powerless to stop the paranoia spreading across the population. While the world searches for a criminal mastermind to blame for this tragedy, two mysterious children - children who shouldn't even exist - masterfully carry out their heinous plan. Cursed to walk through this world with the names Nine and Twelve, the two combine to form "Sphinx," a clandestine entity determine to wake the people from their slumber - and pull the trigger on this world.

After the party of heroes defeated the Demon King, they restored peace to the land and returned to lives of solitude. Generations pass, and the elven mage Frieren comes face to face with humanity’s mortality. She takes on a new apprentice and promises to fulfill old friends’ dying wishes. Can an elven mind make peace with the nature of life and death? Frieren embarks on her quest to find out.