Disclaimer: This review covers the 2020 anime film "Demon Slayer - Mugen Train," also known as "Demon Slayer - Infinity Train." When the first 26-episode season of "Demon Slayer" aired in 2019, it was clear that it was popular around the world, including in the Western country of the USA. But I didn't realize how sensational it was in its home country in Japan. For some anime fans, it was easy enough to ignore if you weren't into the idea of an action-shonen in the vein of "Naruto" mixed with violence and mature themes seen in "Fullmetal Alchemist" and "Attack on Titan." In 2021, the wide release of the sequel film "Mugen Train," it was no longer something to be ignored.That's because, at the box office, it blew records away. In Japan alone, it became the highest-grossing anime film of all time, beating the likes of Hayao Miyazaki's "Spirited Away" and Makoto Shinkai's "Your Name." From late 2020 to early 2021, it remained in theaters for several months in Japan. At the time of this writing, it's on track to make over $500 million USD in theaters. When it released in North American theaters about six months later, a quick turnaround from Aniplex and Funimation (with a complete English dub), it was given not just a limited, one-night release, but a full-out wide release, no different from a Disney movie. And it ranked 2nd-highest at the American box office that weekend. Think about that: it's rare for a niche anime film, let alone any foreign film, to break the top ten American box office, let alone the top three. But how could an anime film, with a story that requires watching the prior television series, be so successful? It just so happens there was a worldwide pandemic in 2020, and theaters everywhere were shut down for several months. When they did slowly re-open, most films to look forward to were pushed back by as much as two years, to avoid the expected reduced profits. But the films, television and games that timed themselves just right, taking advantage of the pandemic and the drought of content with no alternatives to spend time, made bank. "Mugen Train" released in late 2020 in Japan, at a time when the virus was mostly under control, and having a generous run before cases spiked again in 2021. For millions of film-goers eager to see something, ANYTHING, in a theater, and with few new options to choose from, "Demon Slayer" was an easy go-to for audiences. Had the film released in any other year, I'm certain it would have made less than half what it profited.And there's another reason why fans would be especially eager to see "Mugen Train," a reason I haven't seen other journalists address: its story is canon. In films for any other major anime franchise (think "Naruto," "Fairy Tail" or "My Hero Academia"), the stories are original and self-contained, having no impact on the main story. If you're a hardcore or casual fan, these "shonen-films" are fun to watch, but completely unnecessary; you could choose to just continue watching the main series on TV and not miss anything. There are valid reasons for this type of story-choice, but it's a common complaint from viewers. But here, "Mugen Train" is effectively a season 1.5: the end of season 1 directly leads to this movie, and this movie directly leads to season 2, which airs in 2021. Important characters die here. If you're a fan and don't want to be left behind, you HAVE to see this movie. ... but do you REALLY need to see it? Honestly, a two-sentence summary to know who dies at the end is probably enough to skip the movie. "Mugen Train" has most of the strengths of the tv series, but also suffers from the worst of it. If you are a fan of the franchise (and only fans that already care need apply), you'll have a great time, especially if you see it on the big screen, but it's also easy and fair to dismiss as a summer popcorn flick.
Again following Tanjiro on his never-ending quest to find a cure for his sister-turned-demon, he and his friends ride a steam train for the first time, bound to a new destination where demons are causing havoc. Leading "Flame Hashira" from the Demon Corps, Rengoku, is also on board for the same purpose. He reveals to them that the issue isn't actually at the destination: demons are on the train itself, and the lives of the passengers are at risk. So Tanjiro and friends need to fight the force, who chooses to use a special power to put them to a deep slumber, fast asleep in dreams of fond memories and desires (this puts them in a vulnerable state where their souls can be swiftly killed in those dreamscapes). As stakes rise, things are worse than they feared... the train ITSELF is the demon, living, breathing, and hungry! For Tanjiro, this gives us a chance to relive his sorrow in his dream for having been away when his entire family was killed by demons (save for his sister, the one survivor). It also gives us some backstory for Rengoku, who is marketed as the poster-child for this specific movie (making me suspect a spoiler that did in fact play out). For scaredy-cat Zenitsu, and loud-mouth Inosuke, their dreams and behavior are almost entirely comic relief. In fact, there's a lot of humor in the movie, groan-worthy and frustratingly annoying, the type of visual gags that would appear in a children's show (you know, something that isn't officially rated by the MPAA as "R"). The villain is also a bit flat here. That's odd, since the villains in the series had so far been given a lot of characterization, helping the viewer sympathize with them, despite their acts as a demon that hungers for human flesh. As powerful as he is, I felt like the big baddies from season 1 were a bigger threat too. To further compound any disappointment in the story, a surprise final act extends the film by 30 minutes, with a brand new out-of-nowhere villain, leading to an emotional loss, but seemingly no gain. Story aside, "Demon Slayer's" strengths were always the production values (visuals and audio), at their best during scenes with action. And yes, "Mugen Train" has plenty of exciting action setpieces. It isn't necessarily better than the television series, but that already looked great and cinematic, so it works great in a feature film. There's enough of it to keep excitement at a high for most of the second-half of the movie. And man, the sound effects and score benefits a lot from a theater's speaker system. The animation and sound alone makes the movie worth watching.(Also, yes, I saw the English dub version in the theater, and during the frequent scenes of awkward comedy, it was as cringe-worthy as it was before, but otherwise servicable when the content itself was.)To summarize, "Demon Slayer - Mugen Train" is fun, exciting action movie. Within the scope of the franchise, it's a "good enough" movie to recommend, and great to watch on a big screen. But it also reminds me that I've probably had my fill of the franchise, especially if this is a sign of the quality of the story going forward. "Mugen Train" doesn't hold a candle to "Spirited Away" or "Your Name.", or a few dozen other anime movies I can name... but the critically-great movies usually don't make nearly as much money as the popcorn-action movies anyway.