English Dub Review: Demon Slayer: Kimetsu no Yaiba “You Must Master A Single Thing”

Overview (Spoilers Below):

Demon Slayer is still caught up in the many horrors of Mount Natagumo as Tanjiro and company attempt to rid the remaining forces of the mountain’s Spider Demon Clan. With Tanjiro and Inosuke occupied with the head of the family, the episode spends the majority of its time with Zenitsu as he deals with his own struggles in his efforts to return to his demon slaying friends. Zenitsu may face less threatening foes, but his situation turns dire when he becomes infected by the demons and begins to undergo a gruesome transformation. Zenitsu’s predicament shifts between the past and the present as he thinks back to his important training lessons with his master, Jogiro, and hopes to unlock the fantastic abilities that lie dormant within him. Demon Slayer creates a strong episode that also works as a parable of sorts as fundamental lessons are placed on the show’s heroes and they begin to prepare for the next wave of evil.

Our Take:

“You Must Master A Single Thing” tackles a difficult task, but it’s one that’s absolutely necessary for Demon Slayer to work as it moves forward. Right from the start Tanjiro is a character who has clicked and it didn’t take very long for Inosuke to prove his worth, too. However, Zenitsu often appears to be the weak link amongst the trio and his presence up until this point hasn’t amounted to much beyond annoying comic relief and a relatively grounded perspective as he approaches obstacles with much more fear and trepidation than his cohorts. Zenitsu’s neurotic routine was just about to reach its breaking point if it went on for any longer, but this installment acts as the necessary pressure release that not only provides some context for Zenitsu’s fears, but it actually helps the audience root for him.

Demon Slayer has played a risky game with Zenitsu, but the anime deserves some respect with holding back on Zenitsu’s much-needed origin story. It feels like the series intentionally wants the audience to build up some vitriol for the character, much in the same way that Zenitsu is harsh on himself towards his various mistakes. “You Must Master A Single Thing” shows that this frustration for Zenitsu’s failures has all been part of the plan and it’s a necessary low that the character needs to hit before he can progress as a fighter. Even though there are some riveting training sequences and some suspense battles against the Spider Demon Clan, the biggest triumph of this episode is how it manages to craft an emotional story around this maligned character and provide him with the redemption that both the character and viewers have been after.

After Tanjiro and Inosuke have done much of the heavy lifting during the “Mount Natagumo Arc,” Demon Slayer cleverly pivots towards the third member of Tanjiro’s troika. Both Tanjiro and Inosuke find themselves occupied with eliminating the patriarch of the Spider Demon Clan and even though their fight looks to contain all sorts of thrilling action, they’re relatively stuck in a standstill. Accordingly, Demon Slayer looks at Zenitsu, who’s been left behind, but does manage to make significant progress over the course of this episode.

While Tanjiro and Inosuke are tied up with the Spider Demon Clan’s ringleader, Zenitsu views the disturbing demon spider babies as enough of a threat. A lot of Zenitsu’s struggles in the present see him on hot pursuit from these creepy infant arachnids, but his situation becomes considerably more desperate when he receives a bite from one of these demons that begins to turn him into one of the eight-legged monstrosities. During Zenitsu’s struggle to stay alive, wipe out the enemy, and stave off infection, glimpses of his past are interspersed throughout the episode. Zenitsu thinks back to his rigorous training with Jigoro Kuwajima, a prolific Demon Slayer, but even though he goes by the nickname “Gramps,” that doesn’t mean that he’s a pushover. The episode shows that Jigoro’s ruthless tactics are largely responsible for Zenitsu’s many insecurities.

These memories are painful for Zenitsu to revisit, but they at least are able to serve an important purpose. Zenitsu goes into a bit of a fugue state, during which he taps into unbelievable lightning powers that seem like they could be even surpass the limits of Tanjiro and Inosuke. Zenitsu is mocked by his target for only having control of one of the three skill-sets that are out there, but Zenitsu merely proves that mastering one thing really well can be more effective than being kind of good at several things. It’s an important lesson, not just for Zenitsu, but all of the characters within Demon Slayer. Funnily enough, Demon Slayer is a series that adeptly handles most of its material and has very few weak links, rather than a show that just does one thing right really well.

To speak to that point, another impressive thing about this episode is that it finds a way to turn Zenitsu’s more annoying traits into oddly endearing qualities. Zenitsu’s worrisome behavior has worn thin in the past and he’s someone that’s more prone to accidentally shout out his weakness than an encouraging battle cry. “You Must Master A Single Thing” revolves around Zenitsu’s growth as a Demon Slayer and visits the most important and inspiring moments through his training process. However, whenever past accomplishments of Zenitsu are looked at, he debases the memories and tries to dismiss them. After actually seeing what Zenitsu has gone through, his negative thoughts create a more empathetic character and highlight how emotionally damaged he really is. He deserves praise, but he won’t allow himself to receive it.

Structurally, “You Must Master A Single Thing” is also cleverly plotted throughout this story arc. It’d be awfully repetitive if Tanjiro went on to eliminate the Spider Father right after he did the same thing with the Mother. Instead, Demon Slayer shows Tanjiro struggle with the challenge and instead bolsters Zenitsu’s skills so he reaches a point where he can join up with his friends and help them defeat their new foe. It takes a story that could have felt manipulative or like a waste of time and uses it to improve the narrative. In that sense, “You Must Master A Single Thing” also creates genuine excitement around Zenitsu’s return to the battlefield and it gives all of its characters renewed purpose. Hopefully Zenitsu won’t suddenly lose his fighting spirit or be unaware of how to reawaken his aggressive side after he’s made such progress. Demon Slayer has been generous lately towards the growth that its cast has made, but shounen series can also have a tendency to develop temporary amnesia  when it’s convenient for drama.

“You Must Master A Single Thing” continues Demon Slayer: Kimetsu no Yaiba’s strong run of episodes and even though this entry trades action for character development, it still creates actual stakes and culminates with one of the more satisfying explosions of power that the series has ever seen. It feels like Demon Slayer has finally finished all of its necessary groundwork as a series and it’s ready to complicate things in a very big way. The Demon Slayers may nearly be through with the dangerous Spider Demon Clan, but their trek through Mount Natagumo is far from finished.