Nihon Hikikimori Kyoukai

The N.H.K. is Tatsuhiro Satou's fabrication of an organization operating off of a subversive government-driven conspiracy, meant to induce Japan's youth into a hikikomori lifestyle, through fictional media and brainwashing.

It stands for Nihon Hikikomori Kyoukai (The Japanese Hikikomori Association, 日本ひきこもり協会), which is a parody of the actual broadcasting organization, Nippon Housou Kyoukai (The Japanese Broadcasting Corporation, 日本放送協会).