Dr. Stone Episode 21

Dr. Stone Episode 21

Spartan Crafts Club

Overall I’d say this was a pretty good episode of Dr. Stone. There were only a few questionable parts, and one of them I think was only included to give Suika’s character some sort of importance. I’ll get to that towards the end of the review, though.

Episode 21 was all about crafting things which will eventually be used to build a pair of cell phones. But as I’ve mentioned multiple times in the past, the term “cell phone” makes this invention sound like it’s going to be familiar to us. Instead, it will likely appear more like 1950s technology than what we have today.

But cell phones aside, I first want to talk a little bit about Ishigami Village as it’s depicted in this episode.

The very first thing I noticed was that the bridges connecting the two islands of the village to the mainland have been reconstructed. This is sort of important, but not as much as you might think. Yes, the islands protect the village from some attacks, but as I’ve already explained last week, Tsukasa’s army could just burn everything down again.

And that “again” is another big reason why the new bridges aren’t all that important. It would be one thing if the village was actually on the islands and the villagers would have had to rebuild off the island, but the village was burned down. So not only did they rebuild the bridges, but they rebuilt the village as well.

The final thing I want to point out here may have actually been there all along. On the main island I noticed a pathway going down to the coast on the left hand side. Was that always there? I felt like there were cliffs on all sides originally.

Santa Claus Confirmed

So getting into more of what happened in the episode, Senku creates a bunch of light bulbs with the help of Chrome and Kaseki. He then uses their water wheel generator to power these light bulbs and strings them up around a large tree. And of course, he did this because it was December 25th.

That’s a nice way to celebrate and all, but nobody else in Ishigami Village besides he and Gen know what Christmas is. I imagine he’ll do this eventually, but it would have been nice to see him light up the village instead of a tree. I’m sure the villagers would have appreciated that more as well.

Senku's Christmas Tree from the anime series Dr. Stone
Senku’s Christmas Tree

But what’s more important about this scene than anything else is that it’s confirmed that Santa Claus exists in the stone world. We don’t know if he was petrified originally and broke free, or if he was never petrified in the first place, but he exists.

So, if he was originally petrified, then who saved him? Maybe he’s a member of the Tsukasa Empire now.

But if he wasn’t ever petrified, then what has he been doing for the past 3,700 years? And how did he avoid the petrification? Is that just part of his magic? Did it not reach the North pole? We need answers.

Computer Assembly

Going back to the inventions of the episode, after creating light bulbs Senku decides that it’s time to make vacuum tubes as well. These are basically what make electronics work. And if you’ve seen 1950s computers, you’ve probably seen the over-sized vacuum tubes Senku has Kaseki making.

But this had me thinking, why is Senku trying to make a cell phone at this point in time? I know, you’re going to tell me he’s doing it so that he can stay in contact with Taiju and Yuzuriha, but my point is that’s all. There are so many easier ways to do that.

I get that communication is easier when you have phones, but as I’ve stated before, Taiju and Yuzuriha are going to have to hide it somewhere. It makes so much more sense to use alternative methods of communication. They could even do something simple like break off the tops of trees in certain ways to signal certain movements of Tsukasa’s forces.

There’s really no reason why a cell phone has to be created right now, and I’d actually go so far as to say it’s a detriment. Sure, there are important inventions being made along the way towards the cell phone, but what if all of their effort went towards those inventions instead?

What if Senku actually did make gunpowder and guns rather than a cell phone? Senku mentioned that they need bat guano which Tsukasa currently controls. But it’s not as if Tsukasa controls the only cave around that has bats inside of it. And there are plenty of other ways to get the materials needed.

So instead of assembling a computer, maybe Senku should work on assembling something else that will actually be useful.


But, building a computer is what Senku has set his sights on for now, so I guess that’s what we’re doing. However, the bamboo filament he was using for his light bulbs is incapable of handling the temperatures of burning phosphorus in the vacuum tubes. So is that the end of his dream?

Well, according to Senku, yes. This is one of the parts of the episode I didn’t think made much sense. Senku isn’t the kind of person to give up. When he sets his mind on a goal, he knows what he has to do to get there. But more importantly, he knows it’s possible to get there because it’s been done before.

So when he claimed that they couldn’t make vacuum tubes because bamboo filament was the best filament in the stone world, that went against everything he’s done up to this point. Modern light bulbs don’t even use bamboo as their filament, they use tungsten, so why would he think bamboo is the peak?

Suika holding scheelite from the anime series Dr. Stone
Suika holding scheelite

As I’ve already said, the reason Senku gives up on science seemingly out of nowhere is because it gives Suika a chance to shine, literally. I’m not sure if I’ve said it in any of my previous episode reviews, but I’ve made it known in my Discord server that Suika barely qualifies as a character. So I guess this was an attempt to make her useful.

The glowing stone she finds is known as scheelite, and it’s a tungsten ore. This is what reminds Senku that he can use tungsten to make a better filament for his vacuum tubes, and so he, Chrome, and Magma head out into the caves to find some more.

Does this mean Magma is going to get some character development? Probably not.


So what do you think of Dr. Stone episode 21? Did you think this was a good or bad episode? I’m going to err on the good side, but this still isn’t my favorite series. And why do you think Senku gave up after his bamboo filament failed? Have you come up with a different reason than I did? Let me know in the comments.

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My review of the next episode is available here.

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2 Replies to “Dr. Stone Episode 21”

  1. I came across this blog and only read your reviews for episodes 19, 20 and 21 (honestly don’t think I could bare to read another with the amount of negativity and the iamverysmart vibe) but it left me wondering if you’ve ever actually enjoyed the show? Many of your concerns, as I’m sure you know by now so I hope you’ve learned how to sit back and just enjoy it.

    1. I don’t think you’ll be a fan of any of my other Dr. Stone episode reviews, but you seem to know that. However, I would like to point out that I generally only take that “iamverysmart” position in regards to things I actually know about. For example, electromagnetism isn’t something I have experience with, so I’m not going to comment on that when it’s brought up in the series.

      Also, I do view Dr. Stone more critically than a lot of other anime simply because it portrays itself as a series about science. A series that claims to be about science getting scientific subjects incorrect is pretty important to point out.

      As for if I’ve ever enjoyed Dr. Stone, I don’t think so. I don’t find it to be an enjoyable series. That’s not to say I think it’s bad, though. I think it’s very average. It does what you expect it to as a shounen series, and nothing more. It has an interesting premise, but I don’t think it capitalizes on that. And the characters are all either bland or way too much like caricatures. There’s really nothing about this series I’m invested in.

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