Warning: The following contains spoilers for Demon Slayer: Infinity Castle
Demon Slayer: Infinity Castle is the hottest anime movie that has premiered in 2025 so far. This is the first installment in the movie trilogy meant to conclude Demon Slayer‘s anime adaptation. Likewise, Demon Slayer: Infinity Castle kickstarts with several references and Easter eggs from the manga that aren’t so easy to spot even for diehard fans.
Demon Slayer‘s creator, Koyoharu Gotouge, has included various references and symbolism in their works, with numerous Easter eggs for viewers to look for that help keep the film fresh and entertaining. These Easter eggs in Demon Slayer: Infinity Castle serve as references that connect the film to the manga, and fans will love finding them.
Kiriya Ubuyashiki’s Appearance Change
Although many fans might think the Infinity Castle is Kiriya Ubuyashiki’s first appearance in Demon Slayer, he has been shown alongside his sisters since the Final Selection on Mount Fujikasane. Kiriya became the 98th head of the Ubuyashiki clan, responsible for leading the Demon Slayer Corps in battle after his father’s sacrifice.
The reason why Kiriya dressed as a woman before succeeding his clan was revealed in the official Demon Slayer Fanbook. Only one son of the Ubuyashiki clan survives to adulthood, and they are raised as women until the age of 13 due to their sickly disposition. However, it’s easy to differentiate Kiriya from his sisters thanks to his black hair.
Doma’s Blood Demon Art Was Foreshadowed in the Anime
During the Upper Moon meeting in Demon Slayer: Hashira Training Arc Episode 8, the lamps can be seen momentarily emitting a blue light before going out before Doma’s arrival. More than just a suspense-building tool, this is connected to Doma’s Blood Demon Art Cryokinesis, which allows him to manipulate ice, as revealed in Demon Slayer: Infinity Castle.
This suggests that the cold surrounding Doma causes the lamps inside the Infinity Castle to go out. This can be seen in the fact that Doma’s palace is the only place without the characteristic illumination of the demonic fortress, depicting various blue tones thanks to a large water garden.
Although his icy powers may be related to Doma’s cold and unemotional nature, the various lotus motifs around him represent enlightenment and are often associated with Buddhism. This is related to the fact that Doma deceives his believers and is worshiped as a religious figure.
Zenitsu Saying Goodbye to His Grandpa
Just as Urokodaki had warned Tanjiro, if Nezuko ever hurt anyone, Jigoro Kuwajima would die after committing seppuku, the Taisho Era’s way of taking responsibility for swordsmen. However, the former Thunder Hashira didn’t request assistance, likely to prevent others from learning the motive and to avoid dishonoring the legacy of the Thunder Breath.
Additionally, in the emotional scene where Zenitsu speaks with his grandfather Jiworo, there’s a river separating them. This means that, although Zenitsu was on the verge of death, he was unable to reach his master because Yushiro was treating him, as the Sanzu River is known as the border between the world of the living and the dead in Japan.
Kaigaku’s Sword Isn’t What It Seems
Although it appears that Kaigaku continues to use his nichirin sword from his time as part of the Demon Slayer Corps, it is actually made from his own flesh. This was revealed in the Demon Slayer Official Fanbook, which indicates that even as a demon, Kaigaku insisted on continuing to consider himself a swordsman.
Because of this, Kaigaku decided to give his flesh sword the form of a nichirin and continue using the different Thunder Breathing forms, but enhanced with his Blood Demon Art, except for the first form used by Zenitsu, which was the only one Kaigaku never managed to master. This indicated Kaigaku’s bad foundation, hinting that he was unbalanced as a swordsman.
Murata’s Non-Water Breathing Style
Murata is a different kind of breath user. Murata has become a recurring character in the anime since the Mount Natagumo arc, but in his appearance during Demon Slayer: Infinity Castle, he is revealed to be using Water Breathing when attacking a demon trying to protect Yushiro and Zenitsu.
While Demon Slayer‘s breathing styles don’t materialize as shown in the anime, as the manga states that people think they can see and feel the various attacks, Murata’s Water Breathing is so faint that it’s not visible at all. This contrasts with other well-known water breathing users, such as Tanjiro and Giyuu.
However, although Murata learned all ten forms of the Water Breathing Style from a master other than Urokodaki, his lack of visual representation can be attributed to his poor swordsmanship. This was revealed in a manga extra and was taken into account when adapting Demon Slayer: Infinity Castle.
Kaigaku’s Past is Linked to the Stone Hashira
During his fight against Zenitsu, Kaigaku’s memories show a group of children briefly glimpsed inside a temple. This scene alludes to the fact that Kaigaku was one of the orphans cared for by Gyomei Himejima, the Stone Hashira, according to his backstory in episode 7 of the Demon Slayer Hashira Training Arc.
Furthermore, by revealing Kaigaku’s human appearance for the first time, as he had only been shown from behind during Zenitsu’s flashbacks, it is confirmed that he was the boy who betrayed Gyomei, causing the deaths of most of the temple’s orphans at the hands of a demon.
This was addressed in an extra in the 17th volume of Demon Slayer‘s manga, where it is stated that Kaigaku went out at night, violating their safety rules. After the children threatened to tell Gyomei that he was stealing money from the temple, he ran and wasn’t present during the attack. Gyomei didn’t discover this at the time due to his blindness.
Akaza’s Blood Demon Art Connects Him To His Lover
Akaza’s blood demon art is not only one of the strongest in Demon Slayer but also a subtle form of foreshadowing his past when he was human. When looking in detail, the pattern under Akaza’s feet when using destructive death is a compass with a snowflake shape.
The snowflake is related to Koyuki, Akaza’s former fiancé, who used a similarly shaped hairpin. Additionally, Akaza’s attacks are named after fireworks, and it was revealed in Demon Slayer: Infinity Castle that when he was Hakuji, he went to see a fireworks show with Koyuki after waiting three years to do so while she recovered.
This scene was an important moment for Hakuji and Koyuki, where they agreed to be together, proving that even after becoming Akaza, he still retained his essence as a human due to his connection with his beloved. Another example is how Doma revealed before that Akaza had chosen to never eat women.
Akaza’s Haori is a Tribute
Koyuki’s influence on Hakuji can be seen not only in his attacks after becoming Akaza but also in his attire. An Easter egg that can be seen in Demon Slayer: Infinity Castle is that the square pattern on Akaza’s sleeveless haori is not an extension of his criminal tattoos, but a character used in the Japanese incense appreciation game “Sanshuko.”
This character translates as “Snow on a Lonely Peak,” and upside-down patterns often represent death in Japan. Given that snow is related to Koyuki’s name and how she used a hairpin with the shape of a snowflake, it means that Akaza subconsciously wanted to pay tribute to his former fiancé, proving he continued to love her even as a demon.
Demon Slayer: Kimetsu no Yaiba Infinity Castle
- Release Date
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July 18, 2025
- Runtime
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155 Minutes
- Director
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Haruo Sotozaki, Hikaru Kondo
- Writers
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Koyoharu Gotouge, Hikaru Kondo
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Natsuki Hanae
Tanjiro Kamado (voice)
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Akari Kito
Nezuko Kamado (voice)
