Temple of Ranma's Sailor Senshi Seifuku

I was thinking.
The elemental countries aren't that big. I mean, a civilian crosses the distance from Konoha to wave country on foot. And that's one fourth of the whole universe!
So narutoverse is in fact an archipelago the size of Japan. Or even smaller.
And we are never shown whats is outside.

Then why couldn't it be an island in the One Piece world? Somewhere in the Calm Belt or in the New World.

Oh how much I'd like to see the adventures of Orochimaru on the Grand Line

I was thinking.
The elemental countries aren't that big. I mean, a civilian crosses the distance from Konoha to wave country on foot. And that's one fourth of the whole universe!
So narutoverse is in fact an archipelago the size of Japan. Or even smaller.
And we are never shown whats is outside.

Beware scale when it comes to Naruto. It´s rather iffy about staying consistent. IIRC at one point it´s stated that Konohagakure to Sunagakure at full run for a shinobi takes about 3 days(and shinobi run FAST).
And i think there was mention that the trip to wave took 2 weeks of walking(don´t think it´s stated if that´s just travel time nor whether it´s only one way), but there´s a lot of statements that makes the place look rather fuzzy around the edges.

Also take note, that the main villages together mobilised 80k shinobi, and that there´s apparently several times more "normal" soldiers than there are shinobi. This gives some minimum sizes for what kind of lands can support those kind of forces without apparently putting all too much strain on the economy.

Japan is probably too small. But possibly not THAT much too small. And the way the land looks(more round/square rather than Japans stretched halfmoonshape), it doesn´t have to take up all that much more surface area on the planet.
My vague guess is that the land is probably twice the area of Japan, maybe three times.

Still, that isn´t actually huge or anything once you change the shape.

Then why couldn't it be an island in the One Piece world? Somewhere in the Calm Belt or in the New World.

While i´m not a fan of OP, so i only have very vague knowledge, i think it´s 100% possible. Might be a bit troublesome to fit in all the "nearby" parts that we don´t really know how far away they are, but much of those are from filler arcs anyway so they can be dropped if they really refuse to fit in.

and that there´s apparently several times more "normal" soldiers than there are shinobi.

What? Where? I thought the armies were all-ninja.

Might be a bit troublesome to fit in all the "nearby" parts that we don´t really know how far away they are,

We actually know precious little of the OP geography. Why? Because it's an ocean world with a bazillion islands and just one strip-like continent.

Anyway, there are precedents of islands laying unknown and unvisited for ages, because of the quirks of the local navigation. Obviously, you have to traverse the Grand Line (practically the world's equator) along its weird and convoluted magnetic trails that run from island to island. If there are islands missed by these 5 or 6 trails, these islands remain unknown.

Then there are the calm belts surrounding the actual Grand Line. No wind, no currents, and *swarming* with Godzilla-class critters. If an island is there, it is *not* visitable, period. And only the greatest heroes would ever reach it. If they know it's there.

What? Where? I thought the armies were all-ninja.

There´s the bigwig lords as well. Remember, Konoha isn´t the capital of the nation, that´s over where the daimyo pretends to be mightier than the ninjas. AND, considering how deferentially the daimyos are treated, it clearly supports that they DO have enough power to be a serious pain in the rear if they want to. And in a world where power is completely based on fighting ability, that means they have SOME kind of army.

It´s impossible to say absolutely for sure, due to how fuzzy the hints we get are, but there´s a number of times when it´s commented about how the ruler of the country have their own soldiers. Apparently NOT chakra-users, as the samurai of Iron(?) nation is considered apart and superior from other nations soldiers, where they effectively replace ninjas locally.

Even just the fact that they are stated clearly to be better than ~"soldiers of other nations because they are chakrausers", tells you that all nations apparently have armies of weaklings as well.

And if the average shinobi that one of the great 5 can muster if needed is 16000 shinobi, and the villages are considered the "few elite" of the nations, well yeah... Personally i think the author pulled something very stupid out of his rear when making things up, not thinking very well about scales used.

Anyway, there are precedents of islands laying unknown and unvisited for ages, because of the quirks of the local navigation.

In that case, you can pretty much assume that there´s no issue about popping in another archipelago or even minicontinent.

, that´s over where the daimyo pretends to be mightier than the ninjas.

More probably it's like in a book I once read: Mages are the real power. But they are so averse to the pain-in-the-ass of actually *ruling* that they chose a king to do the actual ruling while the magic orders play pretend to be under his rule. This way it is *much* less inconvenient for them.
Kind of like a job separation.

I mean, the ninja don't bake their own bread or work the fields, yes?
Maybe ninja make for poor rulers as well.

i think the author pulled something very stupid out of his rear when making things up,

Wholly agree.