However, on the morning of December 18, Kyon arrives at school and finds that the nature of his reality has changed; Haruhi and Itsuki Koizumi are missing, Ryoko Asakura has mysteriously returned, Mikuru Asahina does not recognize him and Yuki Nagato is an ordinary human.

Searching the SOS Brigade clubroom, Kyon finds a bookmark left by Yuki before everything was changed, telling him to gather "keys" to run a program.

Not knowing what the message means, he accepts a dinner invitation from the new Yuki, who reveals a fondness for him because, in this reality, he once helped her get a library card.

Yuki mentions to Kyon that the Data Integration Thought Entity is considering decommissioning her, since continued accumulation of errors is inevitable and will likely lead to further destructive behavior.

The production team decided not to worry about the runtime of Disappearance until the script was finished and the storyboards were at an advanced stage, in order to give ample time to all the necessary scenes; they ended up with seven manuscripts for a provisional total of seven episodes.

[3][4] Directors Tatsuya Ishihara and Yasuhiro Takemoto decided to employ little camera movement to emphasize the atmosphere of the scenes and Kyon's loneliness.

Both directors expressed that it was helpful to have a woman's point of view during the creation process, which was particularly different in regard to the character Yuki Nagato.

[3][5] The studio employed techniques like 3DCG and photography to increase the level of detail in the layouts when the camera panned out far enough that doing it with traditional drawing methods from scratch would be too difficult.

Nishiya put the most care into addressing the posing, gestures, and facial expressions, while Ikeda's role was to ensure the characters matched their design.

For a better result, Ikeda gathered the animation directors at the beginning of the film's production to explain the details of each character design, what to bring out, and what to avoid.

She also gave advice on how to avoid an excessive level of realistic detail to allow for more flexibility in the characters' expressions and body postures during the dramatic scenes.

Sound director Youta Tsuruoka was highly pleased with the result, praising Kyon's voice actor Tomokazu Sugita for his performance.

However, at the close of the 2009 season on October 8, 2009, a 30-second teaser trailer showing Yuki Nagato was aired, revealing that The Disappearance of Haruhi Suzumiya would actually be a film,[9] set for a February 6, 2010 release.

[26] The film's theme song is "Yasashii Bōkyaku" (優しい忘却, "Tender Oblivion") by Minori Chihara, the single of which was released on February 24, 2010.

The soundtrack also contains music from French composer Erik Satie, including Gymnopédies, Gnossiennes and his composition "Je te veux", which were used in the film.

With the film's release on February 6, 2010 on 24 screens in Japan, it placed in the top 10 for Japanese box office sales in its first weekend,[30] and earned an estimated 200 million yen in its first week.

[34] In Thailand, the film was forced by the nationwide floods to be screened only at the Lido Theatre, Siam Square, Bangkok, and only for one day, November 6, 2011.