Thank you Ken. I knew about this, but now I will be more cautious calling myself and other people "otaku". I always consider it a funny, not such a serious term, but I understand it can be taken like that.
As for Hikikomori, among other things, there is an anime that looked very well done but I never had the chance to watch it properly. It is called "Welcome to the NHK"
I think that is an old series. I remember the title, but nothing else. ^^