The Spring Hill Evil Dragon Sealing Incident

This story takes place just over a month before the events of Rescue on Crystal Star. To celebrate finishing her long-form documentary novel, The Collapse War, Xiao Yakumo goes to a photo studio in her hometown to pick up a package. Afterward, she mysteriously disappears near the studio, setting off a journey to save Spring Hill in the Land of Fairies, alongside her former companions Yu and Meruko.