The Crimson Demons, including Megumin and Yunyun, strike fear in the hearts of the Demon Lord's army due to their unparalleled mastery of powerful magic. When Yunyun receives a distressing letter hinting at disaster, she seeks help from Kazuma Satou and his companions. Amid comedic misunderstandings, they discover it's a prank, but Megumin's concern for her clan prompts a journey to her village. As they explore the dazzling Crimson Demons' homeland, they uncover clues suggesting the initial threat was no mere jest.