These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Ass Pull: Arguably Yosuga as a character. Nowhere to be seen, not even as a Chekhov's Gunman, before the Return to DW arc? Check. Nothing to say when her 'little brother' returns after his sudden and mysterious disappearance, despite how much she obviously cares about him? Check. Again inexplicably absent at the party thrown especially for him after his return? Check. No appearance after Toto publicly destroys some Forgeries while it was being streamed live on the internet? Check. It seems like she was just made up at the last minute to have an excuse to humanize Toto Sakigami (the REAL one). And it doesn't exactly help that her death was really anticlimactic, if sad. Hopefully she'll have an Early-Bird Cameo to explain why she was gone for 80% of the series if the anime ever gets a second season.
The Director, Tamaki, is a Psychopathic Manchild in charge of managing the titular prison. He uses his position to initiate mandatory Death Games (he poisons EVERYONE and then sells the antidote in exchange for death game prize money). He forces the Deadmen to take part in Blood Sport and dissects the losers. He has scores of Mad Scientists working under him and created not only the Undertakers, but also the Forgeries.
The worst of them all is Hagire Rinichiro, the real director and Mad Scientist extraordinaire. He is so utterly evil he puts notable evil scientistAlbert Wesker to shame. The atrocities he committed include turning poor Shiro into the Red Man / Wretched Egg and being behind Tamaki's descent into bastardry. Essentially, he is behind everything bad that happens to every character.
Draco in Leather Pants: Though not significantly, this is starting to happen to Genkaku, Toto and of all people Tamaki. Rokuro isn't far behind either...
Germans Love David Hasselhoff: While the manga remains popular in Japan, the anime was not received well by Japanese audiences during its original run. Meanwhile, the anime has become a Sleeper Hit in the United States and rivals Bleach as the biggest draw for the recently revived Toonami, while the English manga release withered to do poor sales and was discontinued after only 4 volumes. Although given the anime's high ratings in the States, it's little wonder why Viz Media has decided to crank a Network to the Rescuefor the manga.
It should be pointed out that Bleach was currently airing the Zanpakutou/Sword Beast arc in the U.S. along with Deadman Wonderland, but Americans loved the sadistic prison anime nonetheless.
Harsher in Hindsight: Any of the interaction between Ganta and Shiro after knowing that Shiro is also known as "The Red Man." The revelations regarding the real personality of Shiro in Chapter 55 only makes it worse.
SHINY SHINY note Taken from the upbeat ending theme. Placing the words over a particularly violent/gruesome moment from the episode or playing it over said moments.
G-Cup titties. note In Episode 1, when a inmate asked what Makina's breast size was, she simply said "I'm a G".
"DON'T MESS WITH THE HUMAN CALCULATOR!" note In episode ten during Rokuro's massive freak out he tell's Senji this when said person's branch of sin doesn't work.
Rokuro in general is starting to become this. note Rokuro's over the top mannerisms and narmy animations which are very similar to Higurashi in style coupled with how many funny lines he has in the english dub have led to this.
"DEATH IS ROCK AND ROLL!" note During episode twelve Genkaku's line in the english dub is switched from "DEATH IS SALVATION!" to said line. It's pretty obvious why.
"Heyooh fahking guyz!" note Genkaku's engrish in episode nine right before shoots and kills some of people from Scar Chain.
"I WANNA LIVE!" note Ganta screams this in the first episode. Usually this is said when someone's playing a video game and they keep on dying.
Moral Event Horizon: For Shiro, murdering Ganta's classmates out of pure jealousy. It is for this reason that she feels that Ganta must absolutely kill her.
Watch Episode 6 in the English Dub and just try to take the rant Minatsuki has about her mother abandoning her for the flowers seriously.
Rokuro's Villainous Breakdown / Freak Out in episode ten. It was supposed to be unsettling, we think, but since his craziness went that far, came literally out of no where, with almost no hint that he actually like this, and the fact that both his voiceactors are clearlyhaving too much fun during it, cemented the scene's status into this trope forever.
No Yay: Some people's reaction to Genkaku x Nagi. But considering the context of their relationship they're not wrong. note Genkaku killed Nagi's pregnant wife in cold blood. Then he tortured him and made him remember that his unborn child was dead. Then he stabbed his friend, and then he killed him. Most fans love the pairing regardless.
Paranoia Fuel: A mad bomber/slasher/whatever busts into your third-story classroom through the window and kills everyone in your class except you. You wake up injured to the bloody mess left behind as the murderer gloats by showing you your girlfriend's severed head. You pass out and wake up in the hospital where you are then arrested for the murders. You protest your innocence, but everyone who could corroborate your story is dead, and no one, not even people who have known you your whole life, believes you- you aren't even sure whether or not you believe yourself. You're sentenced to death for a crime you didn't commit, and your friends' parents have to be restrained to keep them from beating you to death on the spot, only for your cell phone to drop out of your pocket and reveal a video you know nothing about incriminating you by showing you bragging about the murders to your lawyer. The frame-up is so convincing you start to believe you're insane.
Squick: Deadman Wonderland can easily qualify as Squick: The Manga.
Yosuga, too. Where was she when Toto/Hagire first reappeared?
They Wasted a Perfectly Good Plot: After Genkaku was revealed to have survived Ganta's Ganbare Gun, he is never mentioned again. Quite a few fans didn't appreciate being teased that an Ensemble Darkhorse could have made a comeback in the future but were left hanging, and will now probably never know his ultimate fate.
What Measure Is a Non-Badass?: A lot of people keep forgetting that Ganta's fourteen and was an everyday middle school kid before being put in DW. Instead, they call him pathetic, and wimpy, and that 'he needs to grow up'. Never mind the fact that he's actually fairing better than the majority of the audience would if they were suddenly thrusted inside a literal hell on earth.
Woobie: Any of the protagonists could make a claim, but the mother of all Woobies would have to be young Shiro. Goddamn.