It’s a long-standing dictum of mine that Kimetsu no Yaiba is better when it’s being serious.  Admittedly part of that is that those moments tend not to involve Dumb & Dumber, who suck the gravitas out of every scene they appear in (at least in speaking roles).  Generally, though, I find this show does dramatic crescendoes and action blockbusters better than slice of life and levity.  It’s generally not very funny when it tries to be, which is a pretty big hurdle to overcome when trying to be those things.

That would normally be a bad sign for this episode, which kicks off the “Swordsmith ” arc proper. But it worked okay for me, probably because the situation depicted was relatively interesting.  The whole six-armed fighting automaton thing certainly came out of left field – and the idea of such a thing being built (never mind in the Sengoku Period) is a larger departure into science-fiction than Demon Slayer typically embarks upon.  But perhaps we’ll get more explanation on that – if not it’ll just have to be one of those suspension of disbelief moments.

We’re introduced to that automaton via an argument between the hashira Tokitou (Kawanishi Kengo) and Kotetsu (Murase Ayumu). The latter is a young boy, and the argument is over a key the hashira is demanding he hand over.  Tanjirou has no idea what’s going on here, but he’s such a goody two shoes that he can’t help getting himself involved.  That’s fine – Tanjirou being an all-time good boy is essential to his character.  Once Tokitou starts getting rough with the kid it’s a lot easier for Tanjirou to justify interfering – though in his current condition (one suspects even a healthy Tanjirou would have been no match) he’s not able to do much.

To wit, Kotetsu is the scion of the swordsmith family that created the fighting doll, “Yoriichi”, 300 years earlier – via a technology no one can replicate now, which means if Tokitou trashes it it’s trashed for good.  It’s designed as a training partner and that’s how the hashira uses it – eventually severing one of its arms in the process.  Tokitou is certainly a piece of work, completely lacking in any social graces whatsoever.  Kotetsu proves himself to be quite the handful himself, however, eventually drafting Tanjirou into a food and water-deprived training regimen with old five-arms in order to get him strong enough to eventually teach Tokitou a lesson.

That’s a bit silly as Graham Chapman might say, but there’s clearly an important link to Tanjirou through the mechanical man, who was made to have the same face as the swordsman Tanjirou has been seeing in his dreams – Tsugikuni Yoriichi, the creator of the Sun-breathing style.  That was name-dropped at the beginning of the second season and clearly has a significant role to play in Tanjirou’s future.  Factor in the 300 year-old (presumably) sword that emerges from Yoriichi’s neck when Tanjirou finally lands a telling blow and knocks its head off, and it’s clear we’re about to see our hero embark on a new phase of his career.