Demon Slayer: Infinity Castle has given Zenitsu Agatsuma his best battle in the anime, with a fated match against the other disciple of the former Thunder Hashira, Kaigaku. Although it’s a shocking development for a member of the Demon Slayer Corps to ally with Muzan, there’s another major twist to Kaigaku’s story that most fans didn’t see coming.
While it’s no surprise that he didn’t get along with Zenitsu, as the latter was always a nervous wreck, Kaigaku’s appearance took things in an unexpected direction for fans. Kaigaku had only appeared from behind in a flashback until now, and his reveal in Demon Slayer: Infinity Castle proved he was related to the Stone Hashira, Gyomei Himejima.
The Stone Hashira’s Tragedy Was Caused by Kaigaku
Kaigaku’s flashback during his fight against Zenitsu confirmed that not only was he one of the orphans taken in by Himejima before he became the Stone Hashira, but he was the boy that went out at night and ended up making a deal with a demon to spare his life in exchange for the other kids in the temple.
However, while in Himejima’s backstory in Demon Slayer Hashira Training Arc episode #7, it wasn’t confirmed why Kaigaku did it; his motive was hinted at in the film. During Kaigaku’s flashback, he said that he was cursed for stealing money, which alludes to an extra in volume 17 of the Demon Slayer manga.
The manga stated that Kaigaku stole money from Himejima’s temple and was driven away after being discovered by the other children. Kaigaku’s betrayal caused Himejima to awaken his power but also led to the deaths of almost all the children, except for Sayo, as the other kids didn’t believe that he could protect them due to his blindness.
Kaigaku is Irredeemable But Also Relevant to Demon Slayer’s Story
The saddest thing about Himejima’s past is that, due to his blindness, he never found out Kaigaku was missing. The other children lied to him, and Himejima had to hear it from the demon himself. However, being blamed for the incident led Ubuyashiki to invite Himejima to join the Demon Slayer Corps, who would later become the strongest Hashira.
Demon Slayer: Infinity Castle also shows that Himejima saved Shinobu and her sister Kanae, who later asked to become his disciples, according to the Demon Slayer‘s novel “One-Winged Butterfly.” While this means that Himejima’s tragedy was necessary, it also shows that Kaigaku wasn’t cut out to become a demon slayer from the start, as he never cared about others.
Nevertheless, Kaigaku’s twist not only gave more depth to his character and the significance of his battle against Zenitsu but also continued the trend in Demon Slayer that those who become demons are mostly flawed people looking for their own interests. Still, the connection between the characters demonstrated how Demon Slayer‘s powerful storytelling keeps surprising fans.
Demon Slayer: Kimetsu no Yaiba Infinity Castle
- Release Date
-
July 18, 2025
- Runtime
-
155 Minutes
- Director
-
Haruo Sotozaki, Hikaru Kondo
- Writers
-
Koyoharu Gotouge, Hikaru Kondo
-
Natsuki Hanae
Tanjiro Kamado (voice)
-
Akari Kito
Nezuko Kamado (voice)
