While Onani starts out purely as a Death Note parody about masturbation, complete with Light's 'Just as planned!' faces and in-depth planning, it quickly takes a turn for the serious, delving into anti-social behavior, bullying, first loves and, basically, school life in general. Think of it as a realistic school slice-of-life (with masturbation in the girls’ toilet!) about Light, without Death Notes and his popularity, and you wouldn't be far wrong.
NHK deals with many similar issues, such as not making friends out of fear of rejection and hiding away from the world. There's even a 'contract' with a weird girl in both, though what the contracts involve differ greatly. Both are very hard-hitting if you can relate to the struggles and emotions of the series’ respective leads. The only real difference is that, where as there's a good balance between comedy and drama in the case of NHK, the two often being blended together, in the case of Onani it's more along the lines of the story getting progressively darker as it goes on.
I hope Onani gets released in English at some point since I want to own it. But, until then, I recommend everybody ignores the title, as well as their initial impressions and reads it. By the end, you'll more than likely love it, and like me, add to your top manga list. I know I couldn’t stop reading it once I got into it. read more
Both are exceptional insights into the human condition, the concept of belonging in particular. Both great psychological works, and accurately depicted emotions of characters in both series make both an excellent read. These two masterpieces both depict intricate and meaningful messages to its intended audience, which will give them a moment of thought over their social interactions with the people around them.
Off the deep and meaningful essay style writing: Both these series have spots of humor and semi hidden allusions to other popular anime and themes within the otaku sub-culture, which make the angst of the story more bearable for a more casual reader, looking for some laughs.  read more
Both series deal with antisocial behaviors of different kinds, characters who don't fit in. They also have an educational, almost therapeutic feel to them, as the characters portrayed in them are very realistic and self improvement is a major theme in both stories.
I would recommend the anime version of NHK above its manga version though. The depiction of the struggles Satou goes through is much fairer in it, among other things.
Both series deal with an antisocial loser protagonist whose inability to cope with reality lead him deeper and deeper into his delusions and constructed fantasies -- where, ironically, he finally manages to find people like him and form friendships. Ressentiment pushes the escapist digital world angle as its main element, but otherwise they're fairly similar.
Are you a shut-in, scared to go out and living in isolation? If so, excellent - these two are perfect for you!
Me-Teru No Kimochi is the spiritual brother of NHK. In both the main character are recluses (although Me-Teru's lead has been one for far longer) and in both a beautiful woman enters the picture, intent on changing their lives.
NHK is more believable and has a girl with small breasts, Me-Teru has a sillier premise and a woman with big breasts. If in doubt, go with the one with the bigger boobs - that's my suggestion.
Chances are you read NHK first as it is better known so I am going to focus more on NHCE.
So like NHK, NHCE is a manga adaptation from a novel by Takimoto Tatsuhiko, his first novel to be exact. And from the beginning of the story, we instantly see that we're in familiar ground. Takimoto seems to draw all his main male characters from the same model, he himself that is.
Yamamoto could easily be seen as a young Satō, who hasn't become a hikikomori yet. He is a depressed, lazy, immature high school student and a coward, who'd rather hide in his imaginary "cool" world than face reality. Both characters can be painfully relatable too.
Then of course there's the girl. In both stories, a girl, who comes with her own set of problems, helps the main protagonist overcome his pains, and he hers.
The difference is that NHCE has more symbolism, action and fanservice than NHK. read more
it somehow has the same feeling to it. in a way they both are comedy manga with a deeper and nice story.
they both are about a guy who has had it with living normally and a way to get over those problems
Both deal with individuals surrounded by people and situations that are rather psychologically twisted. Both contain very similar types of dark/morbid humor, and main characters with rather "lively" imaginations. The lead females (Aiko/Misaki) also have very similar issues and situations.
The art is quite different but the relationship between Sakai and Shoji reminds me a lot of Satou and Yamazaki. Both feature friends working together on a project. NHK is darker than Baka & Gogh, but both are funny and deal with human relationships and emotions.
The main reason behind the similiarity between these two stories might be spoilerish, but it ultimately lies in the relationship between the two main characters and the mutual use and abuse they make of each other.
Both manga attempt to show the struggles of a shy, unpopular and socially excluded protaganist and how they try to make adjustments to their life by changing the way they mentally approach the world. Again!! is less sensationalised and doesn't really try to play up that it's delving into psychology but rather just gets the job done in a realistic manner. NHK has a less continuity to the characterisation, and I'd say it also has a more stereotypical unpopular main character who is genuinely a bit of a prick, whereas Imamura in Again!! is a genuinely nice person underneath it all.
Overall if you liked the psychological aspects of one you'll probably find some satisfaction from the other. read more
Both Male protagonists have a phobia of interacting with people. The two characters get help to cure their illness but go through a lot of drama and set backs, which puts more mental stress on them. Both protagonists build a deeper relationship with their physician, it helps them to break old habits and keeping them motivated.
Welcome to the NHK, for me, was highly reminiscent of Chobits. the whole time i read it i was thinking "Chobits". NHK has a remarkably similar feel to Chobits, in my opinion. Both, in a way, deal with reality vs the 2D world (anime, manga, games (and persocoms)). Though they have different messages about each. If you want a similar story to NHK, Chobits isn't your best choice, but if you're looking for something that makes you feel the same way, and keep you on the edge of your seat in the same way, it would be a wise decision.
The main male protagonist is a hikkikomori, and the story has some focus on his recovery with the help of the female protagonist(s). Welcome to the NHK is a more realistic story with a heavy focus on hikkikomori issues, whereas Rozen Maiden is a fantasy involving living dolls, but the male protags' struggles in both series revolve around their status as shut-ins.
They both deal with a person who has no dreams or aspirations and have no idea what to do with their life. NHK deals with hikkikomori while Hmizu deals with someone who's just lazy. They both do wild things to try and improve their lives but end up being futile.
The main trio's relationship (and character designs, in terms of the guys) is SOMEWHAT similar to that of NHK. A loser(ish) lead gets pulled into a plan to save himself from being a nobody (NHK = hentai game creation; Spike = exam question theft) by a glasses-wearing intelligent fella, friendship blossoming between the two and an ever-so-slightly crazy girl in the middle of all the psychological foreplay/characterisation. The plots are different but there are some definite similarities.
Both stories center around a male protagonist, trying to get a handle on his life. Oguro (I'll Give It My All... Tomorrow) and Satou (Welcome to the NHK) are both, despite their efforts, considered to be failures by those around them, struggling with work, relationships and aspirations. Both series can be quite demoralising, at times, though offset their bleak themes with humour (though, 'I'll Give It My All' is arguably far dryer). If you found one male lead relatable, then you're likely to connect (in some way) with the other, as well.
Both deal with characters in roughly the same age group that are otakus. As Genshiken comes to a close and the characters start looking for work, it almost works as a segway into Welcome to the NHK, which deals with a similar otaku character who is unemployeed and trying to make sense of his life.
Both series feature a guy with very little ambition as well as a rather somber atmosphere. They also have the ex-girlfriend or in Welcome to the NHK's case the former love interest reappear in to the main characters life throwing the main character in to disarray. And finally they both start off with a very eccentric, and somewhat younger girl entering their life as well as both girls having romantic feelings for the main male characters. Welcome to the NHK is more of a psychological anime and contains drug abuse whereas Yesterday wo Utatte is more of a slice of life about a convenience store worker who doesn't know what to do with his life. read more
Sayonara Zetsubou-sensei and Welcome to the NHK are timely satires. Both series also focus on pessimism and despair, as exemplified by Satou's being a hikikomori, adult-game developer and Nozomu's being a suicidal teacher.