Midway through December, Haruhi Suzumiya, the leader of the SOS Brigade, says that the Brigade will have a Christmas party in their clubroom. For dinner, they will have Japanese hotpot. The brigade members Kyon, Yuki Nagato, Mikuru Asahina, and Itsuki Koizumi start making costumes and decorations for the party. But a few days later, when Kyon goes to school, he finds that Haruhi is not there. Not only that, but Mikuru says she's never met Kyon before, Koizumi is also missing, and Yuki is now the only member of the literature club. The SOS Brigade and Haruhi Suzumiya don't seem to have ever existed. No one in the school has ever heard of her, except for Kyon.