"Guren Hyakkiyakou" is an original Japanese song featuring Hatsune Miku. The song is an answer song to Yuuyami no Ayame Uta, where the girl the woman's childhood friend cheated on her with realized that she was just a person on the side. Over come with anger she transforms into a demon and curses the man, presumably instilling madness in the woman so she'll come and kill them together. This song is featured on the compilation album, Karakuri Manyoshu. Main article: Yuuyami no Ayame Uta / Guren Hyakkiyako