In the anime of Welcome To the NHK, the show that is constantly played nextdoor is Puru Puru Pururin.
We know this character is not from a real show (although it has a website alluding to this), so it's not an external influence.
In the manga, an Ojya the witch is mentioned, along with lyrics from the relevant show:
Please give me the courage in my heart to help me fold away this carpet of sadness and discover the me inside,
Oh yes, the delicate heart of a lady,
Just look in my eyes and tell me you love me,
It's like a fairy tail
Do we know if this is an actual show? If so, is it of any relevance?
In the light novel, the show that is played constantly is Ojamajo Doremi (or Magical DoReMi in English) and a life-size figurine is introduced from Martian Successor Nadesico
Yamizaki declares that the figurine is God and tries to convince Satou to worship it.
Do the choice of these shows have any significance? Are there any (rough) similarities in plot to Welcome to the NHK?
TL;DR - Do we know the show that was in the manga, Do the shows in the light novel have any meaning or were they just chosen arbitrarily?