Welcome to the N.H.K.
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.
That guy over there reminds me of Yamazaki from Welcome to the N.H.K. because he looks at child pornography.