All songs are made by the users of the Vocaloid software. The singers are merely actors portraying whatever role the user wants them to. *The Disappearance of Hatsune Miku* was made by cosMo@Bousou-P in 2007 and may have been based on a bug at the time that caused Hatsune Miku to be removed from search engines.

You can read more about the song here:

https://vocaloid.fandom.com/wiki/%E5%88%9D%E9%9F%B3%E3%83%9F%E3%82%AF%E3%81%AE%E6%B6%88%E5%A4%B1_-DEAD_END-_(Hatsune_Miku_no_Shoushitsu_-DEAD_END-)