Kyushu Plates Understood
by tallskill - updated 2023-7-30
Intro
This took me way too long to do. I figured all of this out through sheer brute forcing. Unfortunately I didn’t find a useful pdf hosted by Kyushu Electric on how the grid system works until after I had already figured it out by mapping hundreds of locations. There is still much I don’t know about Kyushu plates but the knowledge I do have will allow anyone to easily jump in and figure it out further. This may be updated in the future if I find the energy to look at another plate.
A Quick Primer
Kyushu plates operate on a grid system. Each cell within the grid is a 2 km by 2 km square. This grid covers all of Kyushu but the numbering is done on a per-prefecture basis it seems. Cells are numbered from 001 to 999, starting at the most northern part of the prefecture. Cell numbers increase by +1 as they move east. Once they reach a border/ocean it will drop down a row and continue on the most western-most point. It simply goes from left to right, top to bottom. Once it reaches 999 it will begin at 001 once more. For this reason most prefectures will go through all the numbers a few times. Since you can find all numbers in all prefectures this means the meta is most useful for those who know prefecture specific clues.
As an example the grid would look something like this and each square would have its own number.
I believe they use the top left corner of the cell to determine if it falls within a new prefecture or not. Because of this, near borders, really weird stuff can happen like a cell that is 99% within one prefecture having numbers matching a range of a nearby prefecture. You can see this in Miyazaki in the max north, where ranges from another prefecture overflow into it because the cells technically begin elsewhere. Compounding this issue is the fact that there may even be areas within a prefecture where its range is altered and does not follow its traditional borders. For example, in Miyazaki there is a national park that completely stops the range as if it was a border/ocean.
Because of all this, mapping prefectures accurately is extremely tedious as you have to make many pins to confirm nothing weird is happening. Pic related.💀
How Cells Work
As I mentioned in the last section Kyushu plates operate on a grid system where each cell is 2 km by 2 km. These cells are a bit more complex than simply having a number. Within these cells is yet another grid but now it has letters instead of numbers! Cells have sub-grids depending on how densely populated / pole dense the area is. For rural areas you will find cells that have a one letter sub-grid while in more populated areas you will find cells with 2x2 or even 4x4 letter sub-grids. By looking at the Kyushu plate you can tell exactly where you are within a cell to pinpoint accuracy. Because of this, it looks like these prefecture plate maps are sold for lots of money for advertising purposes. :^)
1x1 Cell
These cells have a single square sub-grid that takes up its entire area and are assigned a single letter. This is found in mostly rural areas. They use the letter ヨ (yo).
2x2 Cell
These cells have four letters that are split up into two equal rows of two like so.
ハ (ha) ヒ (hi)
フ (hu) ヘ (he).
In this case “ha” would be northwest, “hi” northeast, “hu” southwest and “he” southeast within the cell.
4x4 Cell
These cells have four letters per row and four rows in total. Like this.
ア (a) イ (i) ウ (u) エ (e)
カ (ka) キ (ki) ク (ku) ケ (ke)
サ (sa) シ (shi) ス (su) セ (se)
タ (ta) チ (chi) ツ (tsu) テ (te)
As I mentioned before these grids are typically found in cities. This means if for some reason you happen to know the exact cell location you can 5k easily. I’d advise against memorizing anything more than a couple of important cell numbers/ranges in major cities however.
Cells With Outliers
According to a Kyushu Electric pdf I found, the letters オ (o) and コ (ko) are outliers of some sort. I think they are only used in 1x1 cells. They don’t really go into detail on them and I haven’t bothered to investigate them.
How To Read A Kyushu Plate
We will use the example of this Kumamoto plate below. 659 at the top is the number of the cell that we need to find. In this case it’s in the capital city. Using the info on the right hand side we can determine our location exactly within this cell’s lettered sub-grid.
To clarify, the east and west numbers indicate your location within that letters square. In this case 011 means we should be in the top left of the ク square.
Row Overflow
I mentioned this briefly in the primer but sometimes rows will not do what you expect them to. This could be due to things such as national parks, districts using their own ranges, how kyushu electric sections things, how the regions are administered, the point is I don't have a good idea. You can look at my Miyzaki plate map below to get an idea of what I’m talking about. Often once hitting the beach the next row does not start on the right number. Sometimes you will find the numbers have overflowed 20km into the next prefecture and other times they are nowhere to be found. (maybe they are reserved or used on island/extend into ocean idk). In general I believe there are usually a few cell overflows per row with some exceptions up to a dozen or more.
So if you plan on plotting your own prefectural map for Kyushu this is something you want to be aware of and if you’re using my prefectural map when playing don’t plonk in the orange regions unless you KNOW you’re in an overflow region. I only marked the northernmost overflow regions, however there are many of them on the western border going into Kagoshima. It is much too tedious to track them down in rural mountainous areas with a gen 2 camera and blurry photos. That being said, for areas within Miyazaki it should be quite accurate. While numbers do repeat, you will have only a few regions to look at and it can be easy to rule out which ones don’t make sense.
How To Use This Meta
The usefulness of this meta depends on how serious you are at learning Japan. This meta somewhat requires that you have the knowledge to know which prefecture you’re in already. Since all of Kyushu has the same plates you will need to know prefecture metas like diamonds, tapes, plates, stop sign fonts etc to use it well.
Assuming you know these metas, this is the approach I would take. I would find the ranges of major cities. For example, Miyazaki city jumps between the 400s, 500s and 600s however it has multiple rows in the center that are in the 500s. With this in mind, if we are in a big city and see a plate with 5 and we know for sure we are somewhere in Miyazaki prefecture we can deduce we are in the capital city.
Some prefectures may have multiple large cities on the same latitudes however. For those, I may not bother memorizing them. Another example may be that another large city has a similar range but is farther north/south after the numbers have begun to repeat. Knowing this meta you’ve reduced your options from being any large city in all of the prefecture to something like a 50/50. Which is quite an improvement! Lastly I just want to point out that Saga prefecture has been sectioned nicely. Its numbers don’t repeat and are split regionally so you can actually learn it quite easily!
Plate Maps
Below are various plate maps for Kyushu. For my Miyazaki plate code map, it's highly accurate. For the simplified versions of it and other prefectures be careful near border regions as it may not be as accurate. Thanks to notagoodplayer who spent time outlining and making the simplified maps for most of Kyushu and brikiiee who made the Kagoshima island map!
Miyazaki Plate Code Map
I spent the past 3 days learning all I could about these plate codes and creating an accurate spreadsheet-based plate map for Miyazaki. Avoid plonking in pink and especially orange areas. Feel free to use it and continue working on it if you see issues. I would’ve liked to create a map overlay but since the earth is unfortunately round I don’t have a map of the prefecture in a projection that preserves distance so it would end up being skewed.
https://docs.google.com/spreadsheets/d/1uMzO1UBCVEW8kXsJ6_HEpqMpGgt7HxJEnraUmiR81fg/edit?usp=sharing
Example of what it looks like.
Miyazaki Simplified Plate Map
I made this before I understood the grid system. I simply went down the prefecture plotting the first number I saw. Seeing the gaps in it prompted me to investigate it further and make my more accurate spreadsheet map.
Kagoshima Simplified Plate Map
Source: soundofsilence
Kagoshima Islands Plate Map
These are the southern Kagoshima islands near Okinawa
Source: Brikiiee
Kumamoto Simplified Plate Map
Source: soundofsilence
Fukuoka Simplified Plate Map
Source: soundofsilence
Nagasaki Simplified Plate Map
Source: soundofsilence
Oita Simplified Plate Map
Oita has two number ranges. In red it begins at the northern peninsula on only the eastern half and continues southwards to Beppu. Once at Beppu it stops and continues this red range, starting on the western half of the northern peninsula and continuing southwards as normal.
The green range begins in the Oita City region and heads south. As it goes south the range strays away from the coastline and Kuju mountains, leaving gaps. It continues south of Taketa until hitting 5 near the border. It then disconnects and covers the mountains and eastern portions of southern Oita that it skipped earlier.
Source: soundofsilence
Saga Simplified Plate Map
Saga has many ranges. However the way they are split makes it a good place for region guessing as you don't have repeating numbers and the ranges all have distinct areas.
Source: soundofsilence
Okinawa Simplified Plate Map
See brikiiee’s Okinawa plate guide.
Credits and Sources
baller - helped me plot locations which helped me get an understanding of the system
brikiiee - for his okinawa maps
soundofsilence - provided some regional codes, knowledge and spent a lot of time making most of these simplified plate maps. Good work!
https://www.kyuden-ss.co.jp/bougokan_uketsuke/img/about_bougo.pdf
This is the pdf I found from Kyushu Electric that explains how the grid system works. I unfortunately found it after I already did 90% of the research so it only confirmed what I already knew.