So most of us Фаны know the song, "Disappearance of Hatsune Miku," right? Well, it wasn't just wrote for nothing. Read еще if Ты want to find out about the story.
A few weeks after Miku was released, her fame had grown to such a large scale that millions of people kept searching "Hatsune Miku" on Yahoo! and Google.
Yahoo! and Google thought that Miku was spam. So when a person would Поиск 'Hatsune Miku,' it would lead them to no where. Which, in other words, means that Ты would not be able to Поиск 'Hatsune Miku' on Yahoo!, Google или YouTube.
The Фаны went crazy nuts, and so the song, "The Disappearance of Hatsune Miku" was created. Seeing the fans' rage because of their action, Yahoo!, Google and YouTube brought back Miku and apologized.
And so, that is why we celebrate 'Disappearance Day' every October. (I don't know the exact date)