Kimetsu no Yaiba: Demon Slayer made its anime debut in April 2019, and has been immensely popular ever since.
The reason why Demon Slayer is so popular is similar to why Attack on Titan became a household name just months after its debut. Namely, the themes, opening episodes, and writing styles of the shows all help to bolster their popularity.
Explaining the popularity of Demon Slayer
Demon Slayer’s premiere episode showed protagonist Tanjiro Kamado returning home to find his entire family, besides his elder sister Nezuko, slaughtered. Opening the show with such a grim fact about Tanjiro's life is an easy way to hook an audience in. This is especially true when your target audience tends to be in the 14+ range and has a better understanding of death and mortality.
Much like Attack on Titan, Demon Slayer uses this initial shell shock to pull the readers in, while also introducing them to the theme of the series. Demon Slayer is all about loss, and having our protagonist lose essentially his whole family in episode one highlights this consistent theme.
The episode also ends by giving readers some hope for a somewhat happy ending. Giyuu choosing to spare Nezuko and allow Tanjiro to try and help her is a great contrast to the loss Tanjiro experiences moments earlier. It highlights that while Demon Slayer is about loss, it’s also about finding hope in every loss you can.
As previously stated, Demon Slayer’s main themes are loss, hope, and perseverance. Relatable themes like these are why Demon Slayer is so popular, as almost everyone understands these feelings deeply. Choosing to show these themes instantly also helps to draw first-time anime fans in, especially critics who say the genre isn’t serious enough.
More appealing than the themes themselves is how we see our protagonists weave these themes into every fight and goal. Demon Slayer S1 shows Tanjiro persevering consistently, whether his body, sword, or both were broken in the process.
A character rarely embodies such human themes so wholly, even more so for it to be engaging. Much like Attack on Titan, the reason why Demon Slayer is popular is because of how human the themes and the cast are. They all have flaws, they can’t all do everything, but they do all experience loss, hope, and are seen persevering till the very end.
One of the easiest ways to be a popular show is to connect with your audience, and Demon Slayer does an exceptional job in S1 and beyond.
A final, major part of why Demon Slayer is popular stems from the show's writing style. Much like Attack on Titan, it truly feels like a “no one is safe” environment for its characters, and plot armor feels non-existent.
Creating this constant sense of worry and dread for the protagonists is a fantastic way to draw audience members in. It also creates that much more real of a connection between audience and character.
When characters actually do perish within this writing style, it also creates memorable and internet-breaking moments, which further boost the show’s popularity. A prime example of this is when Kyojuro Rengoku dies during the Mugen Train arc of Demon Slayer.
Since his initial introduction, Rengoku was a fan favorite and wildly popular with fans and non-fans of the series. Having Rengoku die in such a grotesque shape, yet a poetic moment circumstantially does wonders for how connected fans get to a character/series.
Final thoughts on Demon Slayer's popularity
Demon Slayer is popular because of its fantastic high-stakes writing, great immediate hook to draw audiences in, and consistent pervasive themes.
Demon Slayer followed a similar path to Attack on Titan in terms of its immediate success and popularity. Both shows immediately attracted the viewers with their premiere episodes and captivated them with a brilliant writing style full of consistent and well-illustrated themes.
Unfortunately, while both series’ endings leave something to be desired for most fans, the buildup of both shows up to that point was fantastic. Their rise should be considered nothing short of meteoric and are likely the quickest two growing animanga series in recent memory.