Suzumiya Haruhi no Shoushitsu S01

In mid-December, the leader of the SOS Brigade, Haruhi Suzumiya, announces that she wants to hold a Christmas party in the club room. The members of the Brigade, Kyon, Yuki Nagato, Mikuru Asahina, and Itsuki Koizumi, start making preparations for it. However, a few days later, when Kyon goes to school, he realizes that Haruhi and Koizumi are not in school, and Mikuru claims that she doesn't know him. The situation seems to be that the SOS Brigade never existed... Nobody in school knows Haruhi except for one person, Kyon.