Unfortunate ending, not quite Gantz levels of unfortunate but it's up there. Zombie invasion stuff is usually allegorical, be it about consumerism, materialism, a general decline of societal values, etc., and the origin of the crisis is never really important to the events that unfold, so I don't mind unanswered questions, there will always be ambiguity and mystery in these kinds of stories. But this felt like such a mixed bag of a ride, firstly because it indeed more or less starts as a tale of moral collapse, mental disease, and consumerism, secondly because it's developed in quite a pleasantly unorthodox way given Japan's societal values (which is quite refreshing to this zombie apocalypse genre), thirdly because somewhere along the way the author gets sidetracked writing all sorts of pointless side-stories (Zombie Apocalypse 2: Euro Boogaloo, to name one example, and this phenomenon is also evidenced in the various spin-offs that came from this franchise), and finally because the ending not only feels rushed and anticlimactic, it loops right around to the beginning with Hideo not being able to overcome his delusions.
Criticisms/nitpicks:
1) Why even hint at aliens and why reiterate that hypothesis so many times? Not just the 2ch anons but also in Europe. What was the point of even bringing that stuff up? If it was just an insight on how people cope with these kinds of situations, why not give alternative competing explanations like, I dunno, the wrath of God or something? Why aliens? And why reiterate it ad nauseam?
2) What did mindbreaking Hiromi accomplished? Why leave her fate to uncertainty? Her conflict with Oda felt out of nowhere and her being mindbroken by the Zombie Instrumentality Project was just weird and aimless. They made it a point that there was a kind of autocephalous relation between nests, and if Hiromi was so important as the queen, what exactly was her symbiotic relation with the rest of the brains in her nest? Surely it was not her life experiences otherwise she wouldn't have been driven to insanity by brainchan. And if the nests are able to conjure all sorts of crazy magic (like what they did to Auntie), what exactly was going on and what was ultimately the point?
3) Why was Hideo unable to at the very least move on when it was previously established his lack of connection to people? Yajima said as much, he reveals Hideo's innermost emotions and we can't presume that he was lying. This may explain why Hideo finally defaults to being I Am A Crazy Man even if I find this non-development to be contentious and gimmicky. But when the helicopter takes off, Nakata makes it a point of nothing that there are people down in Tokyo still alive, so why have Hideo live in an utterly devastated Tokyo with no people (???) and talking to himself? What was the point of this? Meanwhile, Nakata enjoys living on Eden island while crushing that fine Auntie Eva puss.
4) What was the point of Takashi's three man fight with Naked Emperor and Kurusu? So that they would just nest up? Why? Wouldn't Kurusu be enough to accomplish this? What was the point of NE and Takashi? Wouldn't the story be exactly the same without these two characters, Takashi specifically?
5) What what the point of masked JK? I get that there are tons of senseless deaths in these kinds of stories, but why have her cling to dear life all up until the final volume, even holding to the rail of the helicopter, just so that the world's sharpest axe cut through her visor?
Shit son, I wrote more about this ending than the manga probably deserves. I thought that it was a decent read up until the mall when Oda is introduced then it goes downhill. The initial chapters have some really poignant takes on the manga industry and does an excellent character study on Hideo Suzuki, with some very candid and even oddly sincere scenes of his relationship, his job, his insecurities, etc. What was an initially very surprising and delightful read then just became schlock. I don't mean to be overly harsh on this manga, and please understand that being fresh out of the ending is indeed colouring my opinion of it as a whole, but I kinda hate what it became, this cynical, pretentious, pointless read that has ultimately only inspired me not to sing the praises of what it did right but to point out the glaring narrative faults of this series and even nitpick with increasing pettiness the pointlessness of certain characters. For all it's worth, if this manga had ended when Hiromi was infected (instead of turning into super zomb), I think it would have been a masterpiece. At some point, it felt only like disposable manga read #3984, which is quite unfortunate given just how strong the first volumes were and how refreshing was the initial development of this story.