On December 18, 2013, which refers to a pivotal date depicted in The Disappearance of Haruhi Suzumiya, the official website for the Haruhi Suzumiya series "vanished" and was replaced by a fake error page containing a hidden link revealing that an anime adaptation of The Disappearance of Nagato Yuki-chan was in production.
18. december 2013, en hentydning til en vigtig dato i The Disappearance of Haruhi Suzumiya, "forsvandt" den officielle hjemmeside for Haruhi Suzumiya-serien og blev erstattet med en falsk fejl-side med et skjult link, der afslørerede at en anime baseret på The Disappearance of Nagato Yuki-chan var sat i produktion.