Now, before you say anything, Yes this is indeed shonen. Welcome to the NHK ran in Shonen ACE so it is a legitimate shonen series. Here at slapped together shonen week we don’t care what a show is like as long as it ran in a magazine aimed at boys in Japan. That said, even though Welcome to the NHK does not look like something that would be a shonen series. It really is ment for the kind of people, specificity Japanese people that all they do is think about manga, or games or how the 3D world does not live up to their 2D reality. Because this series, mostly in its early episodes is a harsh truth disguised as a comedy.
Welcome to the NHK is about a lot of different people with horrible problems that are effecting the main protagonist, who him self has a lot of personal problems. There is one single ray of hope from this one girl who wants to fix him who also has a lot of problems of her own. It can get pretty messed up the obsessions that rub off on him from other people. No spoilers here but I am pretty sure the only one that could be only kind of messed up and mostly funny would be when he gets addicted to MMORPGS.
I think it is one of the best series that represents the the kind of shut in or “hikikomori” culture that has be going on in japan. This is not really about “otaku” it involves them but I would not say the main character is “otaku” in the Japanese sense because he is not focused on just one thing. I think the series can be very, very funny but it is also quite dark epically in the manga version. Though I do have to congratulate studio Gonzo on making a pretty good show that does not 100% fall apart after the first hand full of episodes. I think if you are interested in this kind of thing you will get something out of Welcome to the NHK at the expense of poor poor Saito.