Fact1: only clue is bookmark left by alien version of Yuki, Fact2: Haruhi was whole time along with Itsuki and others formerly from school, Fact3: Taniguchi had used when he travelled back in time to assist Haruhi alias, Fact4: Kyon By manages to convince Haruhi to believe story revealing identity to her as John Smith, Fact5: Itsuki gather SOS Brigade thus bringing keys necessary for program built by Yuki
Output: Following on from the events of The Melancholy of Haruhi Suzumiya anime series, the story takes place from December 18 until December 24, a month after the cultural festival. The SOS Brigade, led by Haruhi Suzumiya Aya Hirano, makes plans to have a nabe party for Christmas. However, on the morning of December 18, Kyon Tomokazu Sugita arrives at school and finds that the very nature of his reality has changed; Haruhi and Itsuki Koizumi Daisuke Ono are missing, Ryoko Asakura Natsuko Kuwatani has mysteriously returned, Mikuru Asahina Yuko Goto does not recognize him and Yuki Nagato Minori Chihara is an ordinary human. Only Kyon is aware that everything is different and no one else remembers anything about Haruhi or the SOS Brigade. The only clue Kyon manages to find is a bookmark left by the alien version of Yuki before everything was changed, telling him to gather keys to run a program. While wondering about this clue, he gets to know the new Yuki, who appears to be quite fond of him. As December 20 comes, Kyon learns from Taniguchi Minoru Shiraishi that Haruhi was at another high school the whole time, along with Itsuki and others formerly from his school. By revealing his identity to her as John Smith, an alias he had used when he travelled back in time to assist a young Haruhi, Kyon manages to convince Haruhi to believe his story. With her assistance they gather the SOS Brigade together in the club room, thus bringing the keys necessary for a program built by alien Yuki. Wanting to go back to his interesting life, Kyon activates the program and goes back in time to the Tanabata of three years ago. After meeting up with the future Mikuru, he obtains an uninstall program from the pasts Yuki, which needs to be shot at the culprit right after the change in the early hours of December 18. Returning to the present, they find the culprit, Yuki, who had borrowed Haruhis power to change everyones memories except Kyons, giving him the choice of which world he would rather live in. Kyon questions himself about his choice and thinks to himself that a normal world without the SOS Brigade and Haruhi Suzumiya would be calm and peaceful and thinks Yuki was tired of everything she had to do like monitoring Haruhis behavior and protecting Kyon, but finally decides that his original world was more interesting and fun. Kyon tries to install the program into Yuki but is stabbed by Ryoko, who had retained her psychotic behavior. Before Ryoko can finish him off, he is rescued by future counterparts of Yuki, Mikuru and himself. He wakes up a few days later in a hospital, where the world is back to normal, but almost everyone believes Kyon had been in a coma since December 18 after falling down the stairs. When Yuki mentions to Kyon how the Data Integration Thought Entity would punish her for her actions, Kyon tells her to let them know that if they ever try such a thing, he can tell Haruhi about him being John Smith and have her alter reality so the organization would cease to exist. As December 24 comes and his everyday life returns, Kyon decides there is still time before he has to go back in time to save himself and decides to join in on the Christmas party.