As the holiday season approaches, Haruhi Suzumiya, the leader of the SOS Brigade, declares that the group will host a Christmas celebration in their clubroom, featuring a traditional Japanese hotpot dinner. The brigade members—Kyon, Yuki Nagato, Mikuru Asahina, and Itsuki Koizumi—begin organizing the event, gathering costumes and decorations. However, just a few days later, Kyon arrives at school to discover that Haruhi has vanished. To make matters worse, Mikuru insists she has never met Kyon, Koizumi is nowhere to be found, and Yuki is now the only member of the literature club. It appears as though the SOS Brigade and Haruhi Suzumiya never existed, and no one at the school has any recollection of them—except for Kyon.