Ending Theme: 「踊る赤ちゃん人間」 - Odoru Aka-chan Ningen by Otsuki
 Kenji and Kitsutaka Fumihiko

Hmm....right, not exactly my kind of music. I also wonder if this is
 the kind of music that a reclusive, Hikikomori sufferer would liste
n to. I would think something more soothing, relaxing - more emo lik
e that song from Evangelion, Komm Susser Todd would be more appropri
ate. But hey, weird animation to go with it! So it's not a complete 
lost.

http://www.designchronicle.com/memento/archives/welcome_to_the_nhk_ep1.html

これが引きこもりの聞く種類の音楽だろうかって英語圏に引きこもりって
概念はないだろうにわかるのかよ！
それにアニメのテーマソングであって主人公が好きな曲ってわけでもないだろう(;´Д`)