Onboard the Thrills: A Journey Through “Demon Slayer: Kimetsu no Yaiba–The Movie: Mugen Train”

Plot Summary:

The animated film, Demon Slayer: Kimetsu no Yaiba—The Movie: Mugen Train, directed by Haruo Sotozaki, starts with Tanjiro, Nezuko, Inosuke, and Zenitsu running to board the back of the train. Once all of them board the train safely, they go through the cabins looking for the Flame Hashira, Rengoku. Tanjiro and his friends were directed to join Rengoku in trying to defeat the demon who had been killing many of their demon slayer comrades on this particular train, the Mugen Train. During the first half of the beginning sequence, Inosuke is in awe and shouting about how he wants to fight the train and shows general fascination for the mechanical being.

Once everyone had settled down, the train’s ticket master comes to confirm their tickets and clip them. Once he has finished clipping the tickets, Rengoku and Tanjiro sense a demon. After they defeat the first demon, another demon appears in another cabin. They easily defeat the second demon and then celebrate with exaggerated movements and words. This, however, was a trap, as they were already asleep and caught in the dream state that Enmu, the Lower Rank One of the Twelve Kizuki, put them in. The film then shifts into their individual dream states.

Tanjiro’s internal dream state is peaceful in a wintry region with his deceased family members. He is lulled into this constructed paradise with his mother and siblings interacting with him as they had once done when they were alive (referencing the start of the story). Inosuke’s internal dream state is a dark and twisting cave. He envisions his friends as his minions, who are on a big adventure to fight the anthropomorphic Mugen Train, who is an evil monster. Nezuko has bunny ears, Tanjiro is a tanuki, and Zenitsu is a rodent. Zenitsu’s internal dream state is a lovely-dovey dream of himself and Nezuko going on innocent dates. He is the savior in his own dream, and the environment is full of fruit trees and rivers. Rengoku’s internal dream state is him telling his father that he has become a Hashira and his father not caring. Inside his dream, he is training his younger brother, Senjuro.

For each demon slayer, there is a young child who ties a rope around their respective demon slayer’s wrist and their own to connect them. Each one infiltrates the demon slayer’s dreams and try to destroy their spiritual core. Rengoku’s spiritual core is surrounded by a sea of flames. He is the first to react and chokes the girl in the real world so that she cannot destroy the core. The child who is responsible for Inosuke’s core also cannot destroy it since she cannot find the object. Even more so, Inosuke’s beast spirit chases after her. The boy assigned to Zenitsu also cannot destroy his spiritual core since he is so obsessed with women that he hates any men entering his personal space. The boy who is assigned to Tanjiro has tuberculosis and enters into his spiritual core state. It is so peaceful, and the sprites lead him to the spiritual core which is the sun. Tanjiro’s spiritual core is tranquil, and the ground is water reflecting the sun. He could not destroy the core due to feeling immense guilt over destroying something so beautiful.

Tanjiro is the first to awake due to Nezuko’s scent in the real world and his ability to smell the demon within the dream. He commits suicide and brings himself out of the state. He asks Nezuko to burn the ropes with her blood demon art, but his friends still wouldn’t wake up. Alone, Tanjiro goes to fight Enmu. Even though he is able to sever Enmu’s neck after a hard fight, Enmu reveals that he has fully fused with the Mugen Train. Inosuke is the second to awake with Rengoku. Zenitsu remains asleep but is able to fully utilize his demon slayer abilities. Rengoku protects five of the cabins by himself, while Nezuko and Zenitsu protect the rear cabins. Tanjiro and Inosuke protect the first three cabins while also trying to cut Enmu’s neck which has been fused with the head of the train.

After a brutal fight, Tanjiro and Inosuke manage to defeat Enmu, stopping the train. During this fight, Tanjiro is sent into the dream state countless times. Inosuke manages to avoid this trap, as his boar head makes it difficult to pinpoint his vision. The train ticket master stabs Tanjiro, making it hard for him to fight later. Rengoku manages to save everyone on the train and lessen the blow of the force that occurs when Enmu is killed. Tanjiro is thrown off the train with Inosuke and is heavily injured.

With Enmu’s death, everything appears to be over until Akaza, the Upper Moon Three, appears and fights a one-to-one battle with Rengoku. Rengoku sacrifices his own life in order to protect Tanjiro, his friends, and the injured passengers on the train. He dies sitting up, talking to Tanjiro and revealing some documents that may help him understand his demon slayer art. Likewise, he gives his final words to Tanjiro to tell his younger brother, Senjuro, and his father. Akaza, in the end, flees the scene due to sunrise. All of the other Hashiras are told through their messenger crows that Rengoku has died. It ends with Tanjiro lamenting Rengoku’s death.

Personal Thoughts:

At first glance, this movie may appear to be just another action movie about the ultimate fight between good and evil, but it is way more than that. Even with a character who does not have much screentime in the first season, we are meant to relate to and grow an attachment to Rengoku. Everything about this movie and its setting is also off-putting, as the dream world is one of the most vulnerable times for any person. To invade a dream and to try and destroy a person from the inside out is even scarier than getting physically hurt in the waking world.

The creators of this movie do an exceptional job about balancing light and darkness (e.g. Inosuke’s dark dream sequence to Zenitsu’s bright dream sequence). The soundtrack of Demon Slayer is also powerful as it creates a mood of suspense, content, pain, and loss. The animation itself is captivating and portrays the expressions of characters beautifully. As aforementioned, the storytelling is spectacular, as we are able to see the past and present and gain familiarity with the characters as well as see where they have grown.

An interesting theme that is present in this movie is the duality of good and evil that exists in both humans and demons. While the demons are essentially all evil, they were once human with tragic backstories. And, while the demon slayers are often seen as all good, we see the cracks in this assumption. For example, Rengoku’s father, the former Flame Hashira, is violent and a drunkard, who did not appreciate his son’s efforts even up until his death.

This duality is also seen in the day and light aspect of the show. Demons are strongest in the dark, as they are burned by the light of the day. It can be drawn as a clear statement that the moment they lose their humanity, they can no longer venture in the world like they once did. An almost fatal decision to who they once were. In gaining strength and longevity, they lose all sense of identity and past connections to who they were and who they loved. Demon slayers, on the other hand, lose the opportunity to gain such strength but keep who they are and those they love.

Following this thought, one of the most significant themes in this movie is family and friendship. Tanjiro’s and Rengoku’s dreams are evident of this theme, as they are focused on their regrets regarding their families. Zenitsu’s and Inosuke’s dream states are more comical by nature, but they also display the theme of friendship (in the form of Nezuko and the entire group). Outside the dream state, Nezuko fights so hard since she is convinced all of humanity is her family—she sees her deceased family members in the people who she saves and protects. Rengoku also gives off the big brother trope, who protects the passengers and his fellow demon slayers to his death. Tanjiro, even with his guilt towards his family, gains an even greater support from them by their afterimages throughout the film. The first and second season, on top of this movie, are centered on the main theme of family.

Overall, this specific movie is a masterpiece in both animation and storytelling. Even a person who has not seen the first season can feel a deep connection to the characters. Especially if you have seen the first season, this movie further deepens that connection. As a last note, the main takeaway that I took from this movie is that “winning” does not equal survival. There are far more important values and achievements in life (e.g. justice and protecting the weak) that hold greater significance in the long run even after one’s death.