"Death Note? Man, I love that anime/movie. What, there was a manga?" This is somewhat of a strange case, as originally the manga was already immensely popular in the West before the film/anime adaptations.
Individual scenes are subject to this as well, even amongst fans who know the manga. The infamous "potato chip" scene was understated and matter-of-fact in the manga, but bring up potato chips in reference to Death Note, and people either recall the over-the-top Japanese dialogue from the anime, or the even more ridiculous English dub of the same scene.
Notable examples of this are certain Narm-tastic moments such as L's reaction to the second Kira mentioning shinigami and Mikami's death. Just like in the potato chip example, the reactions of the characters were far more understated (and realistic) in the manga. And in the case of the latter, the actual death/suicide happens 10 days later and off-screen.
Misa Amane is way more accepted in Japan, Europe and South America than in North America. If she could see fan reaction to her, she'd probably wish the NA Death Note fandom was more like the Batman fandom; she'd be more popular!
Anvilicious: The power to kill (without having to assume responsibility) is evil.
It depends from reader to reader, but many feel this around the second arc (see Ending Fatigue) and some even as early as the first arc. This is a series that prides itself on being a "howtocatchem" Gambit Pileup war between two brilliant, strategic characters... and obviously those with low tolerance for endless mind games are going to rage.
Interestingly enough, the Live Action Films have also followed this sentiment, choosing to end it at the first arc. The TV adaptation is...complicated. It foregoes the Time Skip, but keeps most of the events and characters from the second arc.
Mello and Near also come almost out of the blue, in contrast to the usual pains the story takes to show the plans in action from start to finish.
While we're on the subject of Near, him somehow replacing the Death Note with a fake is viewed as one. Especially the fact that Light didn't notice.
Another on the subject of Near happens in the anime where he was able to pick out Mikami amongst many possible suspects as the X-Kira supporting the true Kira all because Near was currently watching Mikami give a televised speech about continuing to support Kira. However, unlike the anime, the manga makes it clear that Near pieced together Mikami being X-Kira due to being the only suspect that interacted with Kira's chosen spokesperson, Takada.
And in the TV drama's finale, Near was revealed to have faked his Mello personality taking over, all so that Light could become more careless in his deceptions. There was next to no foreshadowing regarding this plot twist, when there was so much more hidden symbolism building up to the Split-Personality Takeover being permanent.
Awesome Ego: Light Yagami the God of the New World. Also, more subtly L — only the world's top three greatest detectives with his own L-screensaver.
Misa's Villain Song comes out of nowhere, has no relevance to the overall story, and is never mentioned again. It feels particularly out of place considering that everywhere else in the story, not a single second is wasted. Furthermore, it's nowhere to be found in the manga.
The famous potato chip scene. In a triumphant moment when Light is taunting L for getting outsmarted by a potato bag, he suddenly takes out a potato chip and eats it in slow-mo complete with dramatic music and narration. Now, Light eating from the potato bag is important to the plot because it throws L off his trail, but there's no need for him to suddenly narrate about eating a freaking chip when he has already explained a few seconds before what he is using the chips for.
Base-Breaking Character: Is Light Yagami an entertaining, genius villain with nuanced motives or an annoyingly smug Invincible Villain with no redeeming qualities who generally succeeds entirely through sheer luck?
The death of L in the original. The fanbase is split between it being one of the most emotionally impactful moments and a tragic loss and those who feel that the death threw a massive wrench into the character dynamics and weakened the series in a way it could never recover from. Some people even prefer the Live-action adaptations for having L win and die after the series.
Which ending is better, the anime or manga? Some that feel Light's send off in the Manga was more fitting he dies a pathetic whiny death to highlight how much of a worm he was. Others feel the anime was better with Light having a more emotionally resonant Alas, Poor Villain moment which some argue manages to swing the anime back up from its Seasonal Rot. The endings clearly go for different tones and radically change how one's supposed to view Light and one's opinion on him (a Base-Breaking Character if there ever was one) will probably dictate one's feelings on the ending.
The name changes and other cultural adaptations for the American Netflix version. Many people decry They Changed It, Now It Sucks! as expected, but others recognize them as a Pragmatic Adaptation of sorts (for example, Light's first name is unchanged and many of the other Japanese names are retained), especially with Japanese actor and fellow geekMasi Oka helping to head the series.
Complete Monster: Light Yagami is a brilliant, egotistical student who finds the titular Death Note and soon embarks on a quest to become the God of a "perfect" world he will create. After killing multiple criminals with the Note, Light flies into a rage when a man denounces his public name of "Kira" on TV, gleefully murdering the man on the spot. Once FBI agents investigate, Light kills them as well, revealing himself to one to gloat and later forcing the man's fiancée into suicide. Later, to eliminate his chief pursuer and rival L, Light pulls a Memory Gambit where he has the Death Note given to a man he knows will misuse it and pulls off a scheme that kills multiple people, including L. Light contemplates killing his own sister when she becomes a liability and only relents because of the scrutiny it will draw. Not even lovers are immune, as he uses one of his two lovers as bait for another rival and forces her to burn herself to death, also eliminating any evidence along with her. When exposed, Light attempts to justify himself as well-intentioned, but is revealed as "nothing more than a crazy Serial Killer."
Die for Our Ship: Misa and Takada for getting in the way of L and Light. Takada gets this from Light/Misa shippers as well, some of whom actually cheered when Light killed her, even though he was only using both of them. To a lesser degree, Halle for getting in the way of Mello and Matt or Mello and Near.
Matt. He appears in a mere sixteen panels of the manga, but is extremely popular in the fandom, to the point where if you were unfamiliar with the series you'd think he was one of the main characters, or that his relationship with Mello was canonically romantic.
Matsuda established himself squarely in this place when he pulled a Crouching Moron, Hidden Badass moment in emptying his revolver in Light when the later attempted to kill Near. Of course before hand he was one due to his carefree attitude.
Soichiro Yagami certainly qualifies. In most of the abridged series of the series he is made to be this supreme badass whom no one will question or talk back to.
Mikami is highly revered by fans for being arguably the most over the top user of the death note and for having a genuinely sympathetic back story. It helps that he's also very pretty.
Beyond Birthday only appeared in the book spin off "The BB Murder Cases" and had a passing mention in the anime and manga, but became rather popular nevertheless.
Naomi Misora for being intriguingly mysterious, and nearly bringing the Kira case to an early end by herself... of course, "nearly" doesn't quite cut it when you're dealing with Light.
Fanon Discontinuity: There's when Light regains his memory and becomes Kira again; some people ignore that and everything that happened afterward, considering Light to have remained L's partner instead. Some ignore what happened shortly afterward, L's death; some accept the previous spoiler, but reject everything that occurred after it; some accept everything until the ending of the series, when Light is killed. Complicating things further, the anime (slightly) adjusts the manga's ending. Light still dies, but he dies with slightly more dignity, managing to escape but then getting killed by Ryuk, who doesn't want to be bored while Light's in prison. In the manga, he has a Freak Out! prior to his death.
There are also fans who don't like the Foe Yay added in episode 25, to the point of pretending it never happened.
A small fandom accepts it as fanservice while a bigger one hates how it made L look like he accepted defeat.
Many fans are displeased by and choose to ignore how Word of God interprets Light and L's relation, and such, in How To Read.
Throughout the series, there are a number of images that just happen to resemble crosses. And in the first opening credits sequence, Misora is seen holding the recently killed Raye Penber's body, looking uncannily like La Pieta art.
The first opening credits also shows a split-second image of Light laying on what appears to be a stained-glass window (in the second opening, this is repeated, only Light is shown more as a festering corpse).
Also in the opening credits is an image of Light handing Ryuk an apple, in what appears to be a crude mimicry of Michelangelo's ceiling painting of Adam and God (With Light as Adam, giving the apple more symbolism, and Ryuk as God, being flanked by Shinigami rather than cherubim). Also note how, in this image, Light has THAT chain handcuffed to his wrist, which leads off-screen. It's speculated to mean that the image may actually be larger, including L attached on the other end.
Seeing that Shinigamis are the Japanese equivalent of The Grim Reaper, Misa Amane is, in the Latin American dub of the series, the Japanese equivalent of Mandy, as both are blonde girls that have the same voice actress.
Higuchi's Porsche 911 suffers from Off-Model in the anime adaptation, where it has a central exit exhaust reminiscent of that found on the Boxster/Cayman models. While the 911 GT3 models for subsequent generations (997 and 991) would feature a central exit exhaust, the Type 2 refresh for the 991 generation would feature, for the first time, a central exit exhaust for a non-GT model.
A Serial Killer named Kira, who kills people with a Sheer Heart Attacknote Although, this Sheer Heart Attack is an Action Bomb instead and is obsessed with keeping his identity secret? It's been done.
Inferred Holocaust: Played With. Dozens of people die every day because of Kira, however while the Kira investigation is meant to stop this the deaths are mostly glanced over and everybody seems to be used to the number of deaths.
On the other hand, when Souchiro pulled the trigger on Light, nobody believed it for a second. Light was so high on the Sorting Algorithm of Mortality that there was no way he was getting shot in the back of the car.
Love to Hate: Light is a delusional Knight Templar and only gets worse with time, but few can deny that he's an intriguing Chessmaster who can match wits with the world's greatest detectives.
Magnificent Bastard: L Lawliet is the world's best detective and the Arch-Enemy and only intellectual equal of Light Yagami aka Kira. Introducing himself by tricking Light into revealing his location by sacrificing a death row inmate, L goes on to pursue Light with unfettered ruthlessness. With only mundane resources at his disposal, L manages to constantly evade Light's supernaturally-backed attempts to kill him and becomes ever-closer to exposing Light for his crimes. Even when Light deliberately loses his memories of his work as a Serial Killer, L continues to close in on his enemy and is only finally killed when Light convinces a Shinigami to take out L by giving its own life. Having left a fail-safe to inform his successors of his passing, L's posthumous machination leaves Near and Mello the field to finally take down Light, leaving his rival to scream and plead for his life before his own death.
The second interpretation may not be that far off, given the creator stated "Light's life was ruined when he got the Death Note." Although this refers more to it being a corrupting influence than it being in control of him.
There are people who genuinely agree with Kira's methods and actually believe that Light was doing good with his murders.
Then there's a third group that doesn't give a shit about the morality and just wants to use the Death Note to kill people for the sole reason that they don't like them. With popular targets including Justin Bieber (to Memetic Mutation at this point) and anyone involved in the production of the American remake.
Misa Amane is a walking blob of Moe. Pigtails, Gothic Lolita, Zettai Ryouiki, squealing girly voice, all topped off with a Yandere personality. She's so Moe that she even Shinigami want to protect her. Also, Sayu.
Light and L have their moments too. Especially L, thanks to his personality quirks and endearing smile.
Don't forget Matt's epic scene of Noble Self-Sacrifice. 16 panels in the manga, less than 2 minutes of screentime in the anime, and yet his character is one of the most popular in the fandom.
Linda (the only female student seen at Wammy's house), has a fan following despite her minor role. She appears very briefly in the manga, and not at all in the original anime series.note However, she might make a very brief appearance Relight 2: L's Successors as the student who asks L what he fears; the character is unnamed, but this is a plausible bit of Fanon.
Paranoia Fuel: Your life can be ended at anytime just by having some Japanese god write your name in a notebook. Moreover, it's implied that this happens all the time. And, the only fate that awaits you or anyone, for that matter is nonexistence.
Near, along with Mello. Some fans are not fond of L's succesors. In fact, Near gets even more bashing than Mello, and even the author said that he was more and more unlikable as the story went on. In-Universe, even Light considers Near to be this, personally disliking him and regarding him as being unworthy of succeeding L.
Mello gets better and better as the second half of the story progresses once he stops angsting and becomes the Crazy Awesome leader of the mafia. Not to mention his faaaaaabulous fashion sense. On the other hand, Near, his rival, falls farther and farther into Replacement Scrappydom for L.
Ron the Death Eater: Soichiro Yagami and Misa regularly in L x Light Fan Fics. Also Rem for killing L. L-centric fics frequently derail Light. Light-centric fics often give L the same treatment.
Ryuk is the Greater-Scope Villain of the series, but many fanfics defending Light depict him as The Corrupter who drove Light to his acts of villainy, downplaying Light's own villainy.
Rooting for the Empire: A case could be made that supporting any of the series' major characters involves this trope, since the primary protagonist is a mass murderer with a God complex, and his various antagonists, while they have lines they refuse to cross, are all rather ruthless in their pursuit of him.
Demegawa. Fans considered him to be a JerkassExpy of J. Jonah Jameson who's merely concerned with increasing his own profits. He even caused one of Light's plans to fail because of his Money Fetish!. Good thing Mikami kills him.
Takada. Whenever fans talk about her, it's either that she was an informed intelligent fool who easily fell for Light's charms or a stuck up jerk, particularly on how she treated Misa. She even gets plenty of flak from fangirls who swore to exact their revenge on her for killing Mello - though it's hard to imagine a worse fate for her than the one that actually transpired.
Seasonal Rot: Apart from the final episode, the second part of the series, that is, everything after L's death, is considered by many to be inferior to the first. Whether this means "quite good, just not as good" or "so bad it never happened" depends on who you ask.
Strawman Has a Point: In-universe, crime rates drop 70% worldwide and wars come to an end as Light's work goes on. Those in dangerous or crime-ridden places might find themselves agreeing with him, or at least forgetting that he plans to move on to killing lazy and unproductive people afterward. And, of course, since he only targets people the police have actually caught, whether or not this has any basis in what would happen in reality is obviously extremely dubious.
Many a fan's reaction to the liberties taken by the TV drama. Especially Light's transformation from a resident genius to a much more average individual, with a habit of catching idiot balls every chance he gets. Then there is L, whose quirks have been completely changed from his manga/anime version, and his Jerkass tendencies were magnified and the amorality of his actions more focused on.
Naomi Misora and Matt are viewed as characters that were greatly underutilized.
Amongst the fanbase, Mello is considered the more interesting character between him and Near since to many, Near just comes off as an L 2.0 knockoff while Mello is portrayed as a dangerous Mafia member. Something that makes his character completely unique compared to L and Near. However, Mello ends up becoming mostly Out of Focus just to continue building up the Light vs. Near rivalry.
Subverted with Matsuda, who was slated to die in Soichiro's place. He was already an Ensemble Dark Horse by this point, so he was spared at the last minute.
From the Drama we have the Mello puppet. Its concept was so bizarre and and mind-boggling, but somehow it was crazy enough to work. Too bad they do next to nothing with it.
To add to that, it's more than a bit jarring that Matt is not in it all. You'd have thought that the creators would've wanted to give one of the fan favorites a time to shine, but due to how the story was adapted, he was written out entirely.
Light defends his usage of the Death Note by citing how wars have ceased entirely since the rise of Kira. Aside from this one comment, the intriguing prospect of Light using the note to end global wars is never elaborated upon.
During his incarceration, Light theorizes that another Kira might be controlling him. This is actually a very interesting concept and would've turned the entire series on its head if it had been true.
The rivalry between Mello and Near is only slightly touched upon.
The whole idea of Mello being Near's split personality in the drama.
L, one of the most epic, most badass heroic antagonists in shonen who nearly took down Kira, ends up murdered by Kira himself. For many fans, he was even cooler than Light and many of them refused to see Death Note after his death.
This applies to pretty much all the characters that meet bad ends, but especially Naomi and Matt.
Naomi was actually an invoked case of this, as she was intended to last longer, but then Ohba realized she was so good at her job that it would strain suspension of disbelief too much that she hadn't caught Light within a few chapters.
Tough Act to Follow: For many readers/viewers, Near and Mello (particularly the former) are inferior follow-ups to the nearly-universally liked L. However, others feel that they're not bad characters on their own, it's just that they have the bad luck of being follow-ups to the nearly-universally liked L. Almost anybody would've come off as a disappointment after him.
Unintentionally Unsympathetic: Raye Penber. Ironically, showing his relationship with his fiancee shortly before he's killed was probably meant to inspire sympathy for him. For many readers/viewers the effect was just the opposite when they saw his treatment of her as controlling and misogynistic.
Unpopular Popular Character: L is seen as a deviant weirdo and Matsuda as a foolish and easily-manipulated putz by the other characters. Outside the source material, L was a massive Breakout Character for his off-beat design, weird charisma, and over-the-top detective style, while Matsuda is appreciated as a Cool Loser with several action hero moments under his belt, having a solid moral compass in a murky world, and for being the one who takes out Light in the end.
Many Western viewers take offense at what they perceive as Raye Penber's paternalistic and condescending attitude toward his fiancée, retired F.B.I. agent Naomi Misora — and, worse, her seemingly contented acceptance of it. Then again, that attitude gets him and his coworkers killed, so he's not exactly portrayed as being in the right. (In the DVD Commentary, her English-dub voice actress Tabitha St. Germain said that that scene was particularly difficult for her.)
A more pervasive one is that the Japanese legal system tends to only prosecute cases where a conviction is assured. Hence, people in countries with higher acquittal rates can find it odd that the series never once brings up the idea of wrongful conviction, with Light always assuming that people in jail really did commit those crimes.
Viewer Gender Confusion: Mello, in the manga. Rem is female but looks androgynous. Also, Near who is male but is voiced by female VAs in both the original and the English dub.
Interestingly, Mello's original name was Near, and vice versa, but an editing error at Shonen Jump saw their names switched around.
Near is even more of this in the drama, where he is actually played by a girl.
Aizawa's "I hate Ryuuzaki and his way of doing things!"
Misa often spends her time whining about Light not loving her, and at the same time, acting like a womanchild who is still a bratty daughter of her deceased parents.
What an Idiot!: Naomi Misora giving Light her real name. In the manga, Mikami gets noticed by the SPK when he is asking Kira for orders... on national TV. Also, Higuchi.
On a similar note, Raye Penber showing his FBI ID to his current target, a potential suspect of being the mass-murdering Kira.
The police when L asks them how they would prove someone was Kira. Each one answers that they would somehow set Kira up so that he was videotaped using his powers. Apparently it takes a genius on the level of L and Light to think of simply tricking Kira into revealing hidden information about the case... even though that's a common police tactic in real life.
To say nothing of L himself - who decides to flat out explain to Kira how he has just narrowed his nationality and location down to Kanto on live television. Had he simply kept the information to himself, he could have caught Light before Near and Mello were even needed.
The Woobie: Matsuda, Rem, Gelus, and especially Soichiro and Sayu. From the movie, Shiori.
Light and Misa, when their memories were erased and were left confined and later tricked into believing that they were going to be executed. Light qualifies in general during the Yotsuba arc, given how innocent he is and how you know his Kira persona is just waiting in the wings for him to regain his memories.
Poor Sachiko Yagami. Just a regular housewife who puts her family above anything, but ends up having to care for a catatonic daughter, while her husband and son both wind up dead. And she has no idea about the real reasons for all her family's misfortune.
Woolseyism: Death Note is a story so intricate that it leaves very little room for changes of any kind... and yet, the anime's dubbing team somehow snuck in this little gem:
Misa: I would never dream of living in a world without Light! L: Yes, that would be dark.