Jack, Kento, and Terry, who are now adventurers, are running for their lives from a ghost! Tatsugoro comes to their rescue and invites them to Nekoya. There, the trio is fascinated to learn that Tatsugoro is the legendary Great Sage. The Demon Lord Lastina reigns over the Demon Capital. As she's spending another day feeling weak and inferior to her mother, the previous Demon Lord, a huge door appears in her room. Beyond the door is a restaurant, inside which she is seated at the same table as Adelheid...