If you're a fan of Demon Slayer, or Kimetsu no Yaiba, you've certainly heard about the upper Moons. Today we will talk about the upper Moons. Well if you don't understand, I'll try to bring a little more about anime so you can fully understand how the anime hierarchy works.
If you still don't know this anime I'll be talking a little more about it. Kimetsu no Yaiba or Demon Slayer is a shounen anime that has gained popularity among anime in its category. It involves a bit of action, adventure, mystery and demons. But calm down, you won't have nightmares at night watching this anime.
Content Index
Upper Moons
The story itself is quite captivating as it involves swordsmen. The plot tells the story of a demon named Muzan who gave rise to a lineage of demons that are called Onis.
And among these Onis there is a hierarchy. In the category of strongest there are the lower moons where in a revolt Muzan himself annihilates them all. Their most loyal subordinates are the upper moons where they are numbered from 1 to 6, thus naming their hierarchical position.
Now that you know a little more about the upper moons, let's get to know each one of them and their classification better. We must remember that some gained notoriety among them and ended up rising, or taking their places.
Upper Moons 6 (old) - Gyutaro and Daki

We can say that these two brothers were inseparable. They gain their prominence in the arc of the Red Light District, being two of the most prominent demons and marked the work. Daki, in turn, became so special that he received praise from Muzan himself.
Both were responsible for defeating several pillars. And in their last fight they gave a lot of trouble to the demon hunters and Tengen the Pillar of Sound. This battle was so intense that Tengen had one of his arms ripped off.
Even with all that resistance, Tanjiro managed to cut off Gyutaro's head while Zenitsu and Inosuke cut off Daki's together.
Upper Moon 6 – Kaigaku

This character was mastered by Jigoro who also trained Zenitsu, before becoming a loyal pupil of Muzan. Kaigaku managed to master the eleven forms of Breath of Thunder. Because of this, he became a more skilled and powerful demon.
Before becoming a Higher Moon Kaigaku swore to protect humans against Muzan's own demons. Because he was very strong, he let pride take over and that was what brought his end, in a battle against Zenitsu himself in the Infinite Dimensional Fortress.
Upper Moon 5 – Gyokko

We can say that this character is the very definition of short temper. Since he got angry very easily. Even more when they spoke ill of their 'arts'. He was quite superficial as well as being quite arrogant.
Gyokko nearly ended Haganezuka's life while he was still working on a very important sword. Furthermore, he was also responsible for nearly killing the Pillar of Mist. And that arrogance was the end of him as Muichiro hadn't died and ripped his head off.
Upper Moon 4 (former) – Hatengu

This character was considered one of the most complex in the work. Starting with his appearance, as he apparently looks like a short and fragile man, he has a very thin and skeletal body. And what catches his attention the most is a huge bulge on his forehead.
Hatengu has a unique uniqueness where it can split into smaller parts and each of these parts can act independently. Most of the time each of these parts represents your feelings and they can be hate, rancor, resentment and so on.
His difference from the others is that when he feels threatened the stronger he is during the battle. Despite all the difficulties Tanjiro managed to defeat him.
Upper Moon 4 – Nakime

We finally arrive at this character who has gained notoriety since he first appeared in Muzan's slaughter against the lower Moons there in the Fortress of Dimensional Infinity. She's that mysterious character that was playing biwa and transforms the whole place to your will.
Nakime took over as the new Upper Moon 4 after Hantengu's death, but she didn't hold the position for long because she was "captured" by Yushiro and quickly killed by Muzan to keep all information about him or his plans to herself. She was the last of the Upper Moons to perish.
Upper Moon 3 – Akasa

This character was very prominent in the infinity train arc. Akaza belongs to the most powerful and skilled group of the Upper Moons. He is also responsible for the death of Rengoku the Pillar of Fire, being a strong, agile, skilled and also quite calculating demon.
Akaza faced Tanjiro again, this time in the Infinite Dimensional Fortress. And after a dramatic fight Tanjiro put in a lot of effort with the help of Giyu managed to defeat him.
Upper Moon 2 – Doma

Don't be fooled by this character, despite his very friendly appearance he is nothing more than a great manipulator where he manages to make others believe he is nice and charismatic. But in truth, Doma is deadly and calculating, so much so that it gleefully devours its victims as if it were doing them a favor.
Doma also managed to defeat a Pillar. In addition to killing Shinobu he almost killed Inosuke and Kanao who came out of this blind right eye battle. While Shinobu was still alive, Kanao managed to inject a deadly poison into Doma, which was slow to take effect. However, it was completely effective in bringing about his death.
Upper Moon 1 – Kokushibo

Finally we arrive at number 1, an almost perfect work made by Muzan, Kokushibo is the strongest demon created by him, and is above the Upper Moons. It's my friends, this one I must say has a lot of baggage since he's the brother of the strongest demon hunter ever seen, that even Muzan himself fears him.
Kokushibo was also a demon hunter until he became the strongest of them all. Once, he managed to master Moon Breath which the anime itself says is the second strongest, second only to Sun Breath.
His battle was the most problematic of all for the Hashiras, as there were three of them fighting at the same time and yet he still managed to kill one of them in addition to killing Genya who had arrived to try to help. Kokushibo was finally defeated by Sanemi Shinazugawa and Gyomei Himejima who were already practically dead.
You may be wondering, but where are our heroes? Well, in this anime you will be surprised by the individualism of each character. This will captivate you even more to follow the unfolding of the plot. Our beloved protagonist is called Tanjiro Kamado.
In the first episode of the anime, he is sensitized to the story of this character who is surrounded by a lot of pain, trauma and the like. Since right away he loses his entire family in a Muzan massacre.
After this event we found our first hashira, which later on will understand its function. In this slaughter Tanjiro has his younger sister transformed into Oni, but even though she is transformed, the two still have a very strong bond that will be of paramount importance for Tanjiro's awakening, who from that moment begins his journey.

