Miharu and Ben are abruptly thrust into a world that shows them a morbid future where the Santa Claus House lies in ruins and all their fellow Reindeer have perished. Knecht, who has aligned with the sinister Drosselmeyer, attacks them, and they are rescued by Mr. Hat and guided to the relative safety of a convenience store. But even here, danger lurks—in the form of a hostile Teppei!

Miharu must unravel the mystery of a red, non-faceless Knecht, the secrets behind Mr. Hat's sword, and the truth behind the mice who have transformed into children. The seventh volume of this thrilling dystopian Christmas saga is packed with even more formidable challenges for Miharu.