細菌汚染 (Saikin Osen)

Background
The song was uploaded to Niconico Video on February 3, 2012 and has gained over 500,000 views since. Its YouTube upload (uploaded by Deino) has over 3,000,000 views.

The lyrics are vague, but a common interpretation is that the song is about a girl being bullied by her classmates. The song is considered "Nightmare Fuel" due to the disturbing and menacing, yet interesting style of the 3DPV. One other theory people will say is that the girl had an illness, that wasn't contagious but many stayed away from her for it, and she got depressed and one lyric in which she says they can't even die with grace possibly means she forced them to die with her.

The "person" in the video is not Hatsune Miku, but Calne Ca, an officially recognized derivative created by Deino.