The name of a very interesting light novel, manga and anime series created by Tatsuhiko Takimoto about Tatsuhiro Satou, a hikikomori, or shut in, who abuses drugs and looks at porn. There are a bunch of other characters with their own problems. A great franchise to get into.
N.H.K is a term coined by the Japanese animation titled "Welcome to the N.H.K" the term is usually used to define a series of negative scenarios that will drive a person to do things completely out of their character. It has been defined as god or an evil organisation bent on ruining peoples lives for no given reason. The N.H.K can differ from person to person and is in some situations completely situational.
see: god karma
Person 1: what has been getting you so down recently? has your N.H.K been after you.
Nihon Hikikomori Kyōkai or Japan Withdrawal Association NHK is an organization that sells anime-related products in hopes to create Otaku that are shunned from society. Its goal is to create shut-ins. They tend to create multiple situations that lead to one being barraged by multiple misfortunes. They are seen as a one percent true conspiracy. They are the Illuminati of anime.
"Bro, you needa stop playin' wit me, yk I got the switch with me at all times."
"Stop chattin' bro, you ain't doin' shit. Don't make me pull up and do something N.K.H.I.G."