I've never ever written a review before, so this will be my first.
There are many things that I want to say about this wonderful manga and the reasons for the which you SHOULD really give it a try if you're still hesitant about reading it or not, but I'll move step by step, just to be clear.


~ STORY: 9

The plot is wonderful and pretty original. I won't go through everything that happens since it's all written in the synopsis but I'm a person who prefers watching anime instead of reading manga. I don't have much time to spend on them and I pretty dislike reading things myself or waiting for chapters to come out monthly, but as soon as I started 'KARNEVAL', I never once complained about this issue.
So, if you're new to manga, or you're a PRO that eats at breakfast 600 chaps of Naruto, either give it a try.

~ ART: 9

Still better than Shingeki no Kyojin (don't hate me for saying this). I like Mikanagi's drawing style as well as her colouring. I find it pretty original it-self and there's always so much detail in everything she draws. What really gets me are the outfits, the richness in the clothes, always inventing something new to make Tsukumo look more cute and Nai look ... more gay than he actually looks. The action and fighting scenes are absolutely perfect despite I think there's never enough of them (and I loved the fact that the same efficiency was kept in the animation, in the anime's episodes). Character's design is original, and despite in the first volumes the art was pretty 'rough' (pardon me for the term, even if quite inappropriate itself) I still find wonderful, sometimes, comparing the last chapters and the smooth and linear style of them to the 'rough' ones of the beginning. Her progress is amazing, and that's exactly what makes me give a full 9 to the ART.

~ CHARACTERS: 5

By the way, less praise for the characters. Now, I'll make a premise, just to be.. frank. I know that out there there are many people saying that Gareki and Yogi are fabulous together and the most original characters that the world and the entire universe have never seen but, unfortunately (or fortunately), we're humans and we have different opinions.

Actually, I must say that what's mostly delusional about all the potential of this manga, is the fact that we have MCs that have a lot potential, and that in the 70% of the cases, goes to waste. To top it all, all we barely know about the side characters is their favourite dish and their fetishes. I'm not saying that we should know life, death and even miracles of Jiki or Kiichi (because describing it as a sadomasochistic relationship I suppose is enough for all the fans) but it wouldn't be too wrong to know more about Hirato, Akari or Tsukitachi.
The 'Adult line' is never getting enough attention, which is always drawn by the MCs: Gareki, trying to be useful but always ending up useless, good only at being a cool and absolutely not a stereotypical tsundere at Yogi, our yellow/silver prince that sometimes goes yandere because he loses the patch that prevents him to transform into a post-human. And, talking about Yogi, he has wonderful powers, is a far more powerful fighter than his happy tree friends but still NEVER uses them; and so, we get to the wonderful Nai, as useful as a tossed tissue.
Yeah, there's also Karoku-sama, but, hey, he's just Nai's mama and being the son of two important physicians or whatever at the Research Tower is no more important, since it's passed 45 chapters. And here we go with Tsukumo. In the last chapters we got to know her past, her dramatic story, and- yeah, I feel sorry for her but I must admit that after all this time, I can't bring myself to like her.
Apathetic. Too much apathetic. I won't say she's worse than Nagato Yuki. But sometimes, she's worse of Nagato Yuki. I won't dare to compare her to Mikasa from Shingeki no Kyojin.
Of course I still like the main characters, because all in all, they look wonderful together, colourful, they have great interactions and they all look like an happy family despite their dark pasts (even Gareki's).
[Have I already said that they're colourful?]
But I still find many flaws, in this aspect, as I said before.
Karneval is not about the MC. I still believe that no manga nor anime is all about the MC, and I'm saying it because, after 5 years of watching anime and reading manga, I believe I have 'built' a sort of experience.
I really do like the side characters, but I'm always getting this impression, that they never get enough care from the mangaka. There's so much to say about Hirato's and his half-brother's relationship, and all we still know about the two of them is NOTHING. If I wanted a sadistic bastard with no past and a smiling grin all over his face for the whole series, thanks- there's Kuroshitsuji. And I won't talk about the fact that the reasons why Tsukitachi joined CIRCUS and other things about Akari, thing that would give him a damn background, are never told. And, hey, wait.

WHAT THE HECK IS CIRCUS, AGAIN?

~ ENJOYMENT: 8

So, yeah, despite all I've said, I'm FULLY enjoying it and I guess you should at least give it a try because the story goes smooth, there are a few twists and sometimes you may even think: "HEY! WHO'S THIS WEIRDO AND WHY DOES HE KNOW X?". Of course you'll get the answer 30 chaps later or you won't even get an answer, but I still think is part of life even asking questions that would forever being unsolved (like why the Universe is expanding if it's infinite, so it shouldn't be expanding nor restricting but who gives a sheet of paper, that's Karneval we're talking about).

~ OVERALL: 7

What I'm always seeing, chapter by chapter, is a lot of material and potential that is always being wasted. Precious space in panels given to unnecessary information, things said about Varugas and Kafka and other organizations when we barely manage to get a grasp of what the heck is everything about, because maybe it was never told, or maybe we just lost track of it and if we did, it was only because the mangaka thought IT WASN'T so important. So we see random characters appear, holding some grudge against some others or suddenly forgetting about their friends, and after 20 chapters or less we still don't know why (not even a hint on the reason) or we see fillers on fillers in every damn chapter of the MCs doing something like sewing, attending parties, going to the sea and attempting to take back someone’s boxers lost in a hot spring, or complaining about how they miss Gareki, instead of giving space to some explanation of what's happening or, for instance, why some dead people are alive.
And I know that this manga is a shoujo, but what really makes me sick is the fact that I'm always getting this never-ending Yoreki scenes, where the fanservice floods all the way and nothing changes: Yogi jumping Gareki and Gareki always punching him back. So, my problem is not with the gay thing or the slight shounen-ai, because I guess lots of mangaka do that, but if the turn of this manga is to bet everything on fanservice, to sell it more, to the point that sometimes it overcomes the plot, well, let me tell you all right now that it's not working.
Or at least give more attention to other pairings as well.