Demon Slayer: Kimetsu No Yaiba is one of the most popular anime this year. Ufotable, the studio behind it, has done a fantastic job translating the style and flair from the manga pages into an animated format. And, with this medium, we're able to see all the more refined details that people might've missed in black and white. There are a lot of unexpectedly subtle aspects to this show, characters are deeper than they appear, plot events are foreshadowed far beforehand, and demons aren't just evil monsters. So, let's look back through the first season and chat about the neatest little details.
10 Tanjiro Is Everyone's Big Brother
There's a reason why people who watch/read Kimetsu No Yaiba fall in love with Tanjiro Kamado. Sure, on the surface, he's a pretty cliche action-anime protagonist. But, the more time we spend with him, the more his subtlety begins to shine. Tanjiro is the ultimate people pleaser, he wants everyone around him to feel happy, safe, and sound. It's why he's constantly in a state of "Caring Big Brother" that Inosuke so vehemently despises. The most extreme examples are when he buys ramen and baskets from villagers and insists on paying, when he looks after the kids in Kyogai's house, and when he mourns for the demons as they turn to ash. Just such a pure boy.
9 Feel, Hear, And Smell No Evil?
Now, this is a bit subjective, but it seems like some people have been overlooking it. Inosuke has an incredibly sensitive sense of touch, Zentisu can hear even the emotions of people next to him, and Tanjiro can smell so well he knows the best course of action to take.
These three all have their own gimmick. They're also most likely a reference to the old proverb "Hear no evil, speak no evil, see no evil". Obviously not in the senses themselves, but rather with one of their six senses helping them detect evil, which in this case are the demons.
8 Nezuko Is Actually Super Buff
Nezuko doesn't eat people; Tanjiro won't let her. He doesn't want her to become fully demon, and she obviously doesn't want to hurt anyone. So, in order to compensate for the lack of "nutrients," Nezuko is constantly sleeping. This also causes her to regenerate much slower than a normal demon.
But, oddly enough, Nezuko is incredibly strong still. Like, much stronger than the average demon. She wins in most contests of strength despite not having a strong build physically. This may be her own special brand of demon blood art, or it may be something deeper that we're just not aware of yet.
7 Muzan Has A Past With Tanjiro's Earrings
The main reason that Tanjiro and his sister had to fight a Termari throwing demon was that Muzan, the first of the demons, recognized his earrings. Tanjiro's "hanafune" earrings seemed to remind Muzan of someone who had almost killed him in the past. In the anime, Muzan has a very brief flashback and sends his goons after Tanjiro and crew, but many people might've missed just how similar this shadowy figure looks to Tanjiro. We won't spoil anything that pops up further in the story, but let's just say that this sort of foreshadowing is common in Shonen anime such as Naruto.
6 Muzan's Blood Is An Alternative Steroid
Throughout the anime so far, Demon's have stated multiple times that the more humans they consume, the stronger they become. But, what about Muzan's blood? It's the catalyst for turning humans into demons, and we've seen what too much of it will do to someone. So, what if an already strong demon is given more of his blood to drink?
Will they be able to consume more? This is another method of strengthening demons that has only been alluded to in the show. Our theory is that it works as both a way to grow and to increase the cap for how many humans a demon can ingest.
5 A Kid With Rare Blood Is Worth Extra Points
It turns out that there is another way for demons to cheat the system. One that works as 50 humans worth of power. This is all dependent on the blood type, according to a former member of the Lower Moons, Kyogai.
This "rare blood" is most likely the O- blood type since it's the universal donor and the rarest of them all. But, this isn't explicitly said in the show, just inferred. Still, this concept of "rare blood" isn't really explored much further and is kind of forgotten about later in the story.
4 Zenitsu Ironically Can't Hear His Own Bird
After passing the Final Selection, the newest of the demon hunters were all given the ancient Japan equivalent of a pager in the form of birds. Most of the students received crows, while Zenitsu alone received a sparrow. Now, as it currently stands in the anime, Tanjiro is the only one with a talking crow that other people can understand.
Zenitsu's sparrow can only be understood by Tanjiro, and the entire scientific method behind these speaking avians is never really explained. But, who knows, maybe Tanjiro and Zenitsu's birds should've been switched. It would make more sense since Tanjiro's crow is morose and Zenitsu's sparrow is a bit more cheery.
3 Inosuke Lived Close To The Final Selection Mountains
It is never explicitly stated, but it seems to be the implication that Inosuke, the pig-head wearing madman, was born in the same mountain range where the Final Selection took place. This would immediately explain how a boy raised in the wild would invent his own style of Breath combat since demons were probably roaming about.
It's also briefly mentioned that Inosuke actually completed the Final Selection challenge the fastest and left before anyone else finished. And if this test took place in terrain he had already lived in, it makes sense that he'd be able to get down the mountain faster than anyone else could.
2 Demons Can Create Inanimate Objects
Early on in Kimetsu No Yaiba, it's explained that demons are able to perform a sort of magic called the Blood Demon Arts. These are literal magic spells, as the demons can cause a wide range of different supernatural events by spilling blood. But, what is oddly ignored, is how demons create literal inanimate objects from blood. Kyogai makes drums, Tamayo makes Temari balls, and it only gets more ridiculous as the story goes on. Perforing magic is one thing, but it's somehow more odd that this sort of "creation" magic demons inherently perform is never questioned.
1 The "Reality" Of The Breath Slashes
And along that same line of thinking, what is going on with the Demon Slayers? Ufotable has done a great job translating the sort of "particle effects" the Breath style slashes have from the manga. But, sometimes it just makes no sense. It's obvious that when Tanjiro is performing Breath of Water slashes, he's not literally creating the water that surrounds his blade, it's just a symbol of his movements. But, what about Zenitsu's lightning? Or how Tanjiro literally breaks his falls with water? Sometimes they're there, most times they're not. And it only gets more confusing later on with styles that use poison, fire, and mist.