Natsuki Hanae Almost Lost His Voice Making The Demon Slayer Movie

The 2020 film "Demon Slayer: Mugen Train" marked several major milestones for the incredibly popular dark fantasy anime "Demon Slayer," both in terms of box office success and the series' storyline itself. Despite being released at the height of the COVID-19 pandemic, "Mugen Train" grossed an astounding $447 million worldwide, blowing past the record set by Hayao Miyazaki's "Spirited Away" to become the highest-grossing film in Japan's history, and the fastest film to earn 10 billion yen (almost $71 million) at the Japanese box office (via Box Office Mojo).

The film itself was also an important turning point in the journey of series protagonist Tanjiro Kamado (voiced in Japanese by Natsuki Hanae and by Zach Aguilar in English) and his fellow Demon Slayer Corps — Zenitsu Agatsuma (Hiro Shimono in Japanese, Aleks Le in English) and Inosuke Hasibira (Yoshitsugu Matsouka in Japanese, Bryce Papenbrook in English) — as they came face to face with an Upper Rank Demon of the Twelve Kizuki named Akaza (Akira Ishida in Japanese, Lucien Dodge in English), marking the first time within the series that they have contended with a threat this powerful.

The events of "Mugen Train" certainly had an immense impact on the "Demon Slayer" story as a whole, and its incredible box-office success further cemented the anime as one of the most popular series in the world. Considering the film's colossal impact, it should come as no surprise that the production of "Mugen Train" was a massive undertaking in and of itself — one which almost cost Natsuki Hanae his voice during the recording process.

In a 2021 interview with Anime News Network, prolific Japanese voice actor Natsuki Hanae (who also voices Ken Kanecki in "Tokyo Ghoul" and Korai Hoshiumi in "Haikyuu!!") admitted that he and his fellow cast members almost lost their voices while recording "Demon Slayer: Mugen Train."

"I was concerned that everyone might lose their voices, since we all recorded with so much seriousness and intensity," said Hanae. "There were numerous battle scenes with lots of background noise, and Tanjiro had his voice raised the whole time. There were also many scenes where he was going through a roller coaster of emotions, so this time I prioritized showcasing those emotions in my acting."

Indeed, there are numerous battle scenes within the film where Tanjiro and his comrades are screaming from start to finish, especially in the climactic final battle between Akaza and the Flame Hashira Kyojuro Rengoku (Hiro Shimono). Following that battle, which ultimately ends in tragedy, the three main protagonists also start screaming and crying to mourn their fallen mentor — another scene that no doubt pushed Hanae's voice to its limit. In any case, it's clear that Natsuki Hanae went above and beyond to capture an intense vocal performance for "Demon Slayer: Mugen Train."