The Mount Natagumo arc is a culmination of 17 chapters in the manga, and 7 episodes from the anime; as depicted in the table below:

The Mount Natagumo arc of Demon Slayer is a tale of suspense, mystery, and horror. Tanjiro and his companions must confront a dark force that lurks in the shadows of the mountain. As they battle demons, little do they know how close they are to losing their own lives.

Mount Natagumo Arc | Summary & Recap

Into the Mountain Forest

Tanjiro, Nezuko, and friends stayed at the old woman’s house until they were fully healed and then received their next mission. They thanked the old woman for her hospitality and headed north-north east, towards the densely forested Mount Natagumo. While trying to convince a scared Zenitsu to come along, they hear eerie sounds coming from the mountain accompanied by an acrid smell. At this, Tanjiro and Inosuke run towards the mountain, leaving Zenitsu behind. As they arrive at the mountain, they see an injured demon slayer sprawled on the ground, asking for help.

As they bent down to help him, he was suddenly pulled back into the mountain. Tanjiro and Inosuke run into the thicker part of the forest. There, a demon lurked in the shadow, next to some dead demon slayers hanging from the trees by spider threads. Tanjiro sees Murata, another demon slayer, who explains how the demon slayers who came to the mountain had ended up turning on and killing each other. Back at the Demon Slayer Corps Headquarters, a crow reports the situation on Mt. Natagumo to the master. He then sends two Hashiras, high-level demon slayers, to go assess the situation.

Slayer Against Slayer | Spiderweb

Furious that Tanjiro took Nezuko into the forest, Zenitsu quickly made for the forest. Tanjiro, Inosuke, and Murata hear an eerie sound. They are then besieged by sluggish walking demon slayers who swing their swords at them, but the trio dodge. Tanjiro notices that their movements are not normal and that they’re being controlled. He discovers threads attached to them which a demon is using to control them. As Tanjiro and Murata fend off the controlled demon slayers, Rui, one of the spider demons, appears and asks them to leave. Afterward, Inosuke uses his spatial awareness to detect the location of the demon controlling the demon slayers.

After some time, Murata volunteers to hold off the stringed demon slayers, while Tanjiro and Inosuke go in search of the demon controlling them. Tanjiro notices that some of these demon slayers are already dead, some have mangled bodies or broken bones, and their attacks are stronger now. They are getting closer to the demon controlling them. Tanjiro throws a puppet demon slayer over a tree branch, getting her tangled in the branches. Inosuke does the same. In a fit of rage, the spider demon mother kills the demon slayers she’s been controlling and sets down a hulking headless monster.

Both Tanjiro and Inosuke devise a means to kill the demon and, after combining forms, they succeed. Inosuke then throws Tanjiro into the air. As he descends, he lands a blow on the spider demon mother, while she willingly accepts her fate. She recalls her tragic life as a demon, and, as she burns, she warns Tanjiro of the presence of a Blood Moon on the mountain.

The Spider Demon Family

Over at the other end of the mountain, Zenitsu meets a demon with spider legs and a human head and is horrified at the sight. Upon running away, he stumbles upon a house hanging from threads in the sky. There are humans hanging in various stages of transforming into demons. The spider demon son crawls out of the house, and Zenitsu finds out he’s been poisoned. He, too, would soon become a spider demon.

Despite being weighed down by the poison already coursing through him, and an army of human spiders, he swiftly and quickly killed the spider demon son. His bird flies off to get help. He uses his breathing techniques to slow down the poison, but soon falls asleep.

Meanwhile, Tanjiro spots the spider demon's daughter. As she runs away, her father steps in to fight against Tanjiro and Inosuke. After a series of attacks, they find out that there’s no way they can beat the demon, as their attacks have no effect. At the same time, Giyu Tomioka and Shinobu Kocho, the Water and Insect Hashiras, arrive at the mountain to assess the bodies of the dead demon slayers. They split up to cover different parts of the mountain.

Shinobu and Giyu, Insect and Water

As Shinobu arrives at Zenitsu’s location to administer an antidote to help neutralize the poison in him, Tanjiro and Inosuke continue fighting the spider demon's father. Tanjiro buries the demon under a big log of wood, but, as he strikes a finishing blow, the demon uses the log of wood to throw him far away into the mountain. After Tanjiro falls, he sees Rui punishing his demon sister and confronts him. As they talk, a demon slayer walks in and attempts to kill Rui, but is cut to pieces, much to Tanjiro’s surprise and fright.

Tanjiro prepares to fight Rui. Inosuke hides from the spider demon father, too injured and scared to fight. He summons his courage, and, after a series of attempts, he ends up cutting the demon’s right hand and watches it run away. He goes in search of it and watches it morph into a bigger and scarier demon. He ends up snapping his swords while trying to attack the demon. As the demon holds him up and is about to crush his head, Giyu jumps in and slashes its hand, saving Inosuke. In a single strike, Giyu kills the demon and binds a rambling Inosuke to a tree.

Blood Moon Demon | Giyu, Shinobu, Nezuko

In Tanjiro and Rui’s battle, Rui snaps Tanjiro’s sword using a string. As he tries to kill Tanjiro by encasing him with webs, Nezuko jumps out and protects her brother, an act which leaves Rui stunned. Rui then proposes to have Nezuko become his sister in exchange for sparing Tanjiro, to which Tanjiro vehemently refuses. Rui shows Tanjiro that he’s a Blood Moon and the duo resumes their fight. Rui then abducts Nezuko and locks her with strings somewhere up in the trees. At another side of the mountain, Shinobu Kocho encounters the spider demon sister, and injects poisons into her, killing her.

Tanjiro combines the water-breathing tenth form, his Hinokami Kagura, and Nezuko’s blood demon art to behead Rui. Just when he thought he’d won, Rui stands up and spins some murderous blood webs. Tanjiro is too weak to even move his arms. He accepts his fate. Just in the nick of time, Giyu Tomioka arrives at the scene, saves Tanjiro, and actually beheads Rui.

In his final moments, Rui remembers his childhood as a sick child who had to live indoors all his life, how he met Muzan and became a demon. A short while later, Shinobu arrives where Giyu and Tanjiro are. Seeing another demon, she attempts to kill Nezuko, but Giyu steps in to stop her, an act which greatly surprises Shinobu.

The Kakushi (the Demon Slayer Corps’ cleanup crew) arrived at the mountain and started clearing up the bodies of the dead demon slayers and tending to the injured. While Giyu and Shinobu fight, Tanjiro carries Nezuko and makes a run for it. Then, Kanao Tsuyuri, another demon slayer, jumps in and chases Nezuko. Just as Shinobu is about to stab Giyu with a blade hidden in her shoe, a crow flies in bearing a message and instructs them to bring Tanjiro and Nezuko to the Corps’ headquarters, alive.

Mount Natagumo Arc | Analysis & Review

Storyline | 10/10

Mount Natagumo serves as a captivating narrative arc, intricately weaving the established characters into a thrilling and perilous scenario. This particular storyline unfolds with unexpected twists and turns, offering viewers a deeper understanding of the enigmatic demons within the mountain's depths. As the arc draws to a close, it becomes a pivotal catalyst for the introduction of the Hashiras, who represent the elite, most formidable members of the Demon Slayer Corps, injecting a new layer of intrigue and power into the series. Saying this arc is good is a complete understatement! This arc undoubtedly has the best fight scenes, the best storyline, suspense, and I particularly liked the way it ended.

In telling the story of Tanjiro, Zenitsu, and Inosuke’s first mission together, this arc focuses on the strengths, limits, and weaknesses of each of these characters. It also provides a look into Tanjiro’s first original breathing technique, Sun Breathing, when he used the Hinokami Kagura against Rui. I can’t say that I enjoy seeing the main character almost dying at the end of every battle, but seeing how this arc ended for Tanjiro and his friends, I have to say, it was worth it.

But for this arc, there are some minute differences between the manga and the anime adaptations of this arc, some of which are:

• The manga doesn't have the short scene at the beginning where Zenitsu and then Inosuke chase Tanjiro for Nezuko's attention.
• In the manga, only three of the spider demon son's underlings attack Zenitsu, but in the anime, almost one hundred of them attack him.
• The manga does not include the scene where Shinobu and Giyu arrive at Mount Natagumo to investigate the situation.
• When Rui decides to kill Tanjiro in the manga, he throws threads at him. In the anime, he throws two whole webs at Tanjiro.
• When Rui ties and suspends Nezuko and makes her bleed, the anime depicts her blood falling on Tanjiro’s sword, while in the manga, it falls on his face.
• The origins of the spider family are explored in greater depth in the anime, and one of Daughter's memories is seen for the first time, both of which were left out of the manga.

Character Development | 9/10

This arc featured three major characters, but the focus on each of these characters wasn’t equal. While Tanjiro got the most out of screen time and development, Inosuke and Zenitsu only managed a small amount of focus. Maybe that’s to be expected of side characters.

It was funny yet ironic to see the brash and brave Inosuke run from a demon. Even he remarked that that was his first time running from an opponent. While everything ended up okay in the end, the fear of Zenitsu dying struck me more than anything, especially since the poison kept coursing through him even after he already killed the demon.

I especially like how the story introduces a host of characters like Murata, Ozaki, and Shinobu Kocho. It is evident that this arc serves as the perfect floor to introduce the Hashira, the Demon Slayer’s strongest warriors to the fray, and we get to see them in action.

The Water and Insect Hashiras, Giyu and Shinobu, act as the knights in shining armor when their juniors are in the face of certain death. Undoubtedly, even Inosuke finally understands that he can never be the strongest wherever he is and that even he could die at the hands of a stronger opponent. You could see that from how quiet he was when the Kakushi came to move him.

The entire spider demon family played iconic roles in helping Tanjiro and his friends discover new strengths. This is evident in Tanjiro’s new skill; fusing his water breathing with Hinokami Kagura, to create a stronger and more effective strike.

Art and Animation | 9/10

Hailing from the same studio responsible for the visually striking Fate/Zero (Ufotable Inc.), we are presented with yet another breathtaking visual spectacle that's nothing short of an eye-catching extravaganza. In a time when subpar 3D animation often dominates the scene, it's truly refreshing to witness a studio that has mastered the art of immersive visuals.

It's important to highlight Ufotable for its exceptional animation and character development. Remarkably, there isn't a single instance in the series where the quality of an episode wavers. The show consistently excels in adapting its battle sequences with a combination of stylistic finesse and cinematic choreography. Each character's movements serve a purpose, effectively showcasing their distinctive fighting styles.

The demon designs are nothing short of menacing, exuding elements that reflect their aggressive nature and chilling expressions. Surprisingly, amidst all the intensity, there's still room for humor, particularly evident in the exaggerated emotive performances of characters like Zenitsu. Even our protagonist, Tanjiro, has moments that will leave a lasting impression. Additionally, the anime leverages a realistic, unforgiving setting of forest-covered mountains to vividly illustrate the harsh conditions of wilderness survival.

In essence, what truly stands out in this show is the incredible work by Ufotable and the director. Their dedication and skill deserve every bit of the praise they receive. If you're in doubt, I'd recommend watching episode 19; it serves as a compelling testament to their talents.

Sounds and Music | 8/10

The music and the soundtrack employed in this series play a pivotal role in crafting an enthralling atmosphere. During the initial episodes, it became evident that the show had the power to convey its narrative solely through the evocative and melancholic soundtrack. This synergy between the sounds and the characters truly left a profound impact.

The opening theme, "Gurenge" by LISA, exudes a sensational aura that weaves a compelling visual narrative of its own. On the flip side, the ending theme, "from the edge," imparts a sense of serenity tinged with a touch of loneliness. Together, these musical elements serve as more than just background noise; they're integral in shaping the show's emotional depth and resonance.

Overall Score | 9/10

The Mount Natagumo arc is an absolute delight. It's a rollercoaster of excitement, keeping me hooked with thrilling battles and the stunning, lifelike animation that brings the demon-infested forest to vivid reality. The intriguing plot twists and character growth added layers to the story, making every episode a pleasure to watch. The creators' meticulous attention to detail, coupled with the emotional depth of the characters, made this arc a truly enjoyable experience within the series.