Preface

This guide is targeted to the A202KC/A203KC and 902KC/903KC with mentions of info for the KY-42C.

It's mostly a collection of random bits of information I had to research or figure out.

My A202KC

If you are new to Japanese flip phones, then know that these phones are a hassle to get set up, and are not really made to work outside of japan. These two phone models generally work in NA and some parts of Europe from what I can see but you will need to do your own research on if they will work for you, and even if they do work there is a non-zero chance they won't work outside of cities in specific countries, or in other cities. I've also heard that in Australia a lot of Keitais are blacklisted, but the 902KC seems to work fine.

To preface, the A202KC is the successor to the 902KC. The 902KC is well documented and tested on this sub, I do not own the 902KC but have used posts on the phone for the A202KC since they are virtually the same minus a few differences.

This will include info for features, troubleshooting, customisation, rooting, GPS, and any other tidbits that I hope will be useful to someone. I'm still working on some things though, and will attempt to keep this post updated with any new relevant info, if you have anything to share and add to this post please leave a comment :).

I'll also link any guides or comments I found useful throughout this guide.

Versions

902KC / 903KC / 904KC / A202KC / A203KC / A204KC

For context, the 902KC/903KC are the exact same phone but simply with different providers. 902KC is from Softbanks and the 903KC is from Y!Mobile. This is the same situation for the A202KC/A203KC.

As far as I am aware the only difference is going to be what provider shows up when you boot up the phone, but there are rumours that the software on the 903KC is better built to handle international bands (source). The band compatibility is the same on both providers websites.

Because of this annoying naming scheme I'll just be referring to them as 90XKC/A20XKC.

There is a 904KC that seems to be a camera-less version for businesses. I have also seen sites that mention a A204KC, I assume this to be largely the same situation as the 904KC.

KY-42C

This phone is less well documented on the sub but is very alike to the A20XKC. The phone has different bands then these two phones and I have heard that the compatibility is good for parts of the U.S. It also features an upgraded CPU that can be rooted like the A20XKC (and runs Android 10!).

The bands are on the provided spec page below but in case you can't access it the 4G bands are: (1, 3, 5, 12)

Specs (Requires a VPN connection to Japan)
Blog post from Wiggle on the KY-42C

Differences

Here's links to the specs for both phones:
A20XKC
90XKC

I'd recommend checking out this post from Snoo-98535, they go into depth having had both phones but I'll give you a rundown here as well.

Android:
90XKC runs android 8.1 while the A20XKC runs android 10. This helps a lot with app compatibility, and I have yet to have any significant issues on the A20XKC in terms of apps. I have seen people having issues due to the android version on the 90XKC however. They also both operate on Android go.

CPU Speed:
From what I have heard the A20XKC feels much faster then the 90XKC.

Rooting: Because of the new CPU chip you can root the A20XKC with MTKclient, the 90XKC cannot be rooted or the bootloader unlocked.

Hardware: A20XKC loses the flashlight and pedometer.

Storage:
The A20XKC will have less internal storage due to a larger OS. Both phones have only 8 GB of built in storage, 90XKC uses 2.7 GB while A20XKC uses 4.4 GB. I am getting by fine with this storage restriction however, especially with making use of my SD card heavily.

Network/Bands

If you are not familiar already with bands it's incredibly important that you look into them before buying a Japanese flip phone. These phones are made only to work in japan with international compatibility being more of an afterthought. If you don't look into it and just buy the phone there is a very real possibility that it will not work at all. And of course you need to make sure that the phone is sim unlocked. For an approachable introduction I recommend this guide (This section is mostly taken from that guide).

Band compatibility

90XKC
A20XKC

(The far right column is international band support, the circle means it supports that frequency. LTE = 4G)

A selling point from Kyocera on the A20XKC is that it has more band compatibility, but comparing these side by side the only difference is that the A20XKC now has access to Band V in the 3G spectrum.

To check if the phones bands are compatible with where you live use this website: https://www.cellmapper.net/map

You can check various providers and the bands that they support. Specifically you will need to make sure it works on the 4G bands. Consider also where you may travel to and if you would get signal there. If you cannot find your provider it is likely because it is a MVNO, look up which infrastructure they operate on and plug that into Cellmapper.

You should aim for at least 2 compatible bands in your area. I would also advise against bothering with contacting your provider about these phones as they usually will just tell you to get a new phone if it doesn't work.

APN Settings

In order to get 4G you are going to need to manually input your providers APN settings. To do this search "(Provider) APN Settings". Your provider will have a website with the APN settings for you to input into the phone (look for "Access Point Names"). I really recommend you use screen mirroring for this. After entering this restart your phone.

Troubleshooting

There are various carrier specific issues with this phone, and if you have issues with it you can try looking up your carrier on this subreddit to see if anyone's been having similar issues on these phones.

Threads on carrier specific issues:
T-Mobile
Mint

There also seems to be weird specific sim card issues, mentioned in this post.

If you have 4G but are having trouble with VoLTE (Voice over LTE) and mms:

Input a new APN separately from the one earlier and set it as this:

Names: ims
APN: ims
APN Type: ims

And make sure that you keep your carrier APN selected. And restart.

I found that mine only registered after setting APN protocol and APN roaming protocol as IPv4/IPv6 in both the ims APN and my carriers APN.

On the 90XKC it seems possible to access a hidden cellular testing menu with a shortcut maker that will allow you to force LTE bands. In this post they mention that it helped them to force VoLTE to enable. I couldn't get any similar menu on the A202KC however.

If you are having trouble using data here are some troubleshooting steps for you to try out:

Turn off GSM, select 3G/4G instead.

What worked for me strangely was that I re-flashed my phone. Maybe it just kicked it into working, or maybe debloating specific software before setting up your APN's can mess with registration and such. You can also just try factory resetting if you want to give it a shot.

Buying

The A20XKC and 90XKC are not sold outside of Japan by Kyocera or any carriers.

Regardless of where you buy the phone, you will need to make sure that it is Sim Unlocked, or "Sim-Free" as it is sometimes translated. If somehow you end up with a Sim Locked phone, check the troubleshooting section.

To get one of these phones the options are either a reseller that ships to your country or buying used on the secondhand market. For the used market you can go on second hand sites like Kijiji and find a variety of reputable sellers there. There is also the option of Japanese auction sites like Zenmarket. You can find mentions of Japanese auction sites to check in the subreddit.

Getting Started

This section will go over setting up the phone and tools you can use for modification.

For a quick rundown of the default keyboard, the button with a cassette is the back button. The hang up button (with a power icon) hangs up the phone, terminates whatever app you are in, and shuts down the phone when held. To type a space with the default keyboard use the D-Pad right key. The bottom right custom key can be held for the cursor, and the II custom key can be held to pull up the notification panel.

The phones do not come with any way to install apps natively so we will need to side-load them in order to install them. We can install an app store onto it though and install apps from the device once set up.

First we will need to set up ADB (Android Debug Bridge) which will allow us to connect the phone to a computer and install apps.

Go into Settings>About Phone, in here click Build Number 5 times (It will say "You are now a Developer!"). We will now have access to Developer options which will be in Settings>More Settings>Dev Options. In here find USB Debugging and enable it. Now we can make use of ADB and Vysor/Scrcpy.

Download ADB here.
Download USB Drivers here

For this version of ADB, extract it and run ADB. Throw your apk files into the folder and in ADB type:

adb install (name of your apk).apk

You can rename the apk to make this easier as well.

Once downloaded just plug the phone into your PC (Make sure your cable supports data transfer) and press allow on the phone. If the option comes up make sure to press "always allow" so that you can have an easier time if you have an issue such as getting locked out. Now we can use ADB to install apps onto the phone. To make things easier I'd recommend using a screen mirroring software for the next parts.

Options I'd recommend for screen mirroring are Vysor or Scrcpy for this, both work on Windows, Linux, and Mac. Vysor is plug and play and just works. Scrcpy is slightly more of a hassle to use but is open source and much faster (plus no paywalled features).

I'd recommend installing F-Droid (For FOSS apps) and Aurora Store (For everything else). Alternatively you can just download the apps you want individually online and just side load them through ADB, this will save on file space but these app stores also make updating simpler.

For sake of mind there are a few apps that I recommend you install immediately.

TT9

TT9 is highly suggested across the sub due to these phones using multi-tap natively. For multi-tap you tap the key to cycle through letters. Newer flip phones adopted T9 which is a predictive text system. It allows you to just need to press once for each letter by pressing the corresponding key and it predicting the word based on the letter arrangement possibilities. You can cycle through the options and it will remember which words you use most for better prediction. It can learn your word preferences, and you can add your own words and slang into the dictionary. You can get very fast with this.

Make sure to enable alternative scrolling method if you plan on using the lock screen with TT9 or you will be locked out of the device. On my phone this is in the Appearance settings but it may be elsewhere depending on your version. If you do get locked out because of this, check the troubleshooting section.

KeyMapper

KeyMapper will allow you to change the functions of your buttons, which will allow you to make it a lot easier to use.

When creating a key map you can overwrite any functions already bound to the button, or you can keep the function by enabling "Do not remap" for the key bind in its setting.

You can have have functions bound to single press, double press, and long press.

There are no physical brightness or volume controls, and for sake of mind you really should bind them somewhere. I also have media controls bound to a single button for sake of mind.

Unfortunately Keymapper does not work while the phone is closed, as the phone enters a kind of sleep mode. If this was not the case I would love to be able to control music all with the side button, but it only works to disable or enable manner mode. I end up just having to flip it open and pressing skip and closing it again. Thankfully Bluetooth controls for skipping, pausing, and volume control still work like a charm. I am curious whether inline remotes would work with the right setup as well.

Keymapper also recently introduced folders to the app, which you can assign to app constraints to create app specific profiles. For example on my phone I have the a universal profile for functions I want everywhere, a default profile for general purpose, and specific profiles for things like music players or just for messing around with game streaming and such.

You can also bind a key to tap a specific part of the screen, which I've been using to bind to specific buttons in apps for simpler navigation.

Never set KeyMapper as the default keyboard if you use a lockscreen it will lock you out. If you want to have Keymapper bind buttons to keyboard inputs use key codes (Requires Shuzuku/Sui)[https://github.com/RikkaApps/Sui\].

Unfortunately I've been running into an issue where the app will be killed in the background if the phone starts struggling with a specific task. I am looking for a work around but at times I will temporarily have all my key binds eviscerated for a few minutes while Keymapper desperately tries to wake back up. (This usually happens when I've tried to run a game on the phone).

C9

C9 is a custom cursor app that I heavily prefer to the built in cursor.

The default cursor can select, scroll by moving the cursor to the bottom or top of the screen (not the sides I'm pretty sure), and when holding down select it will enter a scroll mode to scroll the page with the D-Pad. However with this cursor you are unable to press and hold (which makes you need to swap to the D-Pad to do so and then back to the cursor again).

C9 separates the scrolling and mouse movement by allowing you to use the numpad to scroll with swipes in any direction, as well as having dedicated buttons for zooming in or out through gestures. The mouse speed can be customised with acceleration, and you can enable an option to have the mouse go past the edge to the other side of the screen. Also it fixes my main grievance with the original cursor which is that it cannot be used to select and hold. I cannot stress how much easier this cursor makes navigating literally anything compared to the default, I've even been able to use it to access previously inaccessible functions. You can even bind it in Keymapper and overwrite the stock cursor button, and have it tap to toggle instead of hold.

(It also lets you use a custom image for the cursor)

The dev is actively maintaining and improving the app and has directly addressed some of the issues I have faced with it on the phone. Highly recommend!

Apps/Debloating

Apps

For apps I personally strive to use open source ones to avoid bloatware and to maintain privacy. This will keep file size down and allow the most flexibility.

Texting: Oddly there is an issue with the phone receiving sms on any app other than Google Messages and the default texting app. There is an issue with most alternative texting apps where if the app is forced closed using the power button or if battery optimisations kill the app that the phone simply will never show you the text. This can be avoided by always using the back button to close the app and turning off battery optimisations. The phone sometimes forcefully kills apps despite options you have set when it is under load. At the moment the dev of QUIK SMS is looking into the issue, I will update this post if there is an update on that. I still highly recommend QUIK sms but for sake of mind I personally use google messages in the meantime.

Github issue thread
Post on the issue
Blog post mentioning it
[Post on r/garahho](https://www.reddit.com/r/garaho/comments/1go9e80/notifications_other_than_calls_and_sms/)

WhatsApp and Signal work great on the phone, although I can't seem to be able to direct them on where to store images which has been bloating my storage.

Phone/Contacts:

For FOSS dialer apps I've found they all have issues with the numpad when using TT9.

For contacts I use Fossify Contacts.

Music: People have had moderate success with using Spotify Lite on this phone, although it takes up a lot of space.

I'd recommend using a music player app with your own downloaded music in the SD card. There are likely plenty of decent ones on F-Droid.

I personally use PowerAmp (This app has a one time purchase to activate). It's open source, supports my SD card, and has great customization.

In a lot of countries ripping CD's and using the files is legal, and you can buy digital high fidelity music files online from various websites.

Browsers: Vivaldi works generally fine, as well as Brave. Browsing on this phone is not a great experience regardless though and most browsers will just work. Doing anything other than basic web surfing is slow.

Debloating

Thread on apps to remove https://www.reddit.com/r/dumbphones/comments/183mq2l/debloating_question_kyocera_902kc903kc/

Without root UAD can't actually uninstall system apps but effectively disables them instead. This will not save on space but it will help make the phone faster by stopping useless background services. This is a good thing in most cases since you literally can't brick the device because of that. System apps will simply be re-enabled after a factory reset.

UAD can be installed from this source.

Do not uninstall jp.co.omronsoft.iwnnime.ml, this is in the recommended section of UAD but it is the default keyboard and removing it while not having TT9 installed will lock you out.

For a list of bloat check the linked threads, I will also be trying to add these and some I have found to the new UAD fork. Check the issues section on their Github in the meantime as I will be making a post there to request the addition.

Customisation

Launchers

Tip, disable/uninstall the stock launcher and it will stop prompting you to select the launcher every time you restart.

Stock: The stock launcher is very comfortable to use if you get used to it, and it has specific button functions natively built in that just work. Also, consider the fact that downloading another launcher will take up more space. OperatorSlayer

Niagara: This is the one I use in the image posted with this.

Nova: milo_1982

Microsoft Launcher: lovetama_5522

olauncher: lilian0030

Dark mode

Dark mode is hidden in the original android settings app, it can be accessed using something like Activity Manager. Just look for General settings and launch from there. You can also turn on auto rotate, but I believe this is a feature that only works on the 90XKC.

If activity manager does not work on 90XKC you can use QuickShortcutMaker, which seems to work for some.

Here is a guide to do this on the 90XKC with screen mirroring

You can also force it open using ADB

Misc

Phone charms can be added by taking off the back, slide in the charm string and pulling it over the plastic nob.

Hiding Status Bar: Some launcher have functions to hid the status bar on the home screen. You can use ADB to disable it using this method.

I recommend using overscan to hide the nav bar, the above method removes it completely. Overscan simply moves the nav bar off screen instead.. Keep in mind this will hide the functions labelled in the nav bar, but you can learn them since they'll still be functional.

GPS

GPS on these phones is an entire thing where it will take 5 minutes to set up, or in my situation genuine weeks. There are multiple fixes to try, and we will go through them in layers of increasing complexity depending on how much your phone hates you.

To test if GPS is working, enable all the location settings in settings, and see if that works. If it does work, congrats! You can use MicroG to increase accuracy potentially, but if it works fine I really don't recommend it. All these fixes will require services running in the background which will slow your system down and potentially cause issues.

Before we get into it, I should clarify that GPS on this phone is unreliable at best no matter what. Some of these fixes require location services that will need to build up a database of places you go in order to learn where you are. In my case I had given up on GPS and a week later in a café somewhere I randomly tried to get GPS on a maps app and it suddenly started working with perfect precision. Also, if you enter a large building, the GPS will stop working. In my apartment complex it just doesn't work. So just know that GPS will be far from perfect, but it has been somewhat consistent for me.

Layer 1:

Thanks to Fun_Carpet7307
You will need to install MicroG which is an open source application that mimics google play services and also has something called UnifiedNlp built in. UnifiedNlp handles application calls for googles network location provider, so we can use it to add our own location services.

Once installed, go to Self-Check and grant it all the permissions below (especially make sure battery optimisations are ignored). Then go to location and make sure to give it every location related permission. There are two built in back ends you can use (you might need to rotate the screen or kinda finagle it to get to other options)

Then in your phone settings find location settings and put the mode to high accuracy, and in scanning enable all settings,

In terms of location apps very few of them run properly on these phones. I've had trouble with google maps, transit, and quite a few others. OsmAnd seems to work universally for everyone and I've heard good things about Waze but I have not tried it personally. I'd recommend using either of them at first just for testing GPS.

Once you have a compatible maps app, make sure it has location permissions of course and then press the location button, OsmAnd will give an error but this is normal as it is attempting to locate you. Leave the app open for a minute or two afterwards, and if it does not work then the next step is to wait.

Give it a few days and check every once in a while, specifically check while you're outside.

If it starts working for you at this step, congratulations you got lucky.

And if you're unlucky.

Layer 2:

Huge thanks to fivetwofoureight
So until somewhat recently MicroG used to allow you to use your own location back end apps that you could use as modules in the app. They removed this feature and switched to built in options to stay compatible with newer versions of android. We are going to be trying an older version of MicroG that had that feature.

I personally used this option, it didn't end up working for me and I ended up needing to get sig spoofing working regardless and it worked then. Since then I've tried the latest MicroG update and it works perfectly fine as well and have been sticking with that. Your mileage will likely vary with all of this but it's worth a shot if you are on a 90XKC or if you really want to avoid rooting your A20XKC.

The latest version that still had the feature was this.

Now we'll get some back ends. My working setup was Local NLP Backend and GSM Location Service. Local NLP will actively scan on GPS and build a local database to provide location.

There are other back ends you can research and try for yourself online. Mozilla location services have been deprecated so don't use anything that used to relies on it. Once downloaded you can configure them in MicroG. OpenCelliD is an open database which you can download your regions cell tower info from. You will need to create an account and then configure Local NLP and GSM Location using it or an alternative if you can find one.

Once configured do the same process as before, checking maps when outside for GPS every few days.

Congrats! You've done it. It should work now.

Layer 3:

If you're at this stage then you are in the same boat that I was in. It may be an issue related to the A20XKC specifically, but I'm more likely to accept that my phone just hates me.

Unfortunately this step is only possible if you have a A20XKC or a KY-42C. As this step will require us to root the phone.

This will require unlocking the bootloader, rooting with Magisk, installing LSPosed, and downloading FakeGApps. This will allow MicroG to take advantage of Sig Spoofing, which should allow GPS to work properly (hopefully).

For the first step, follow the steps in the Rooting section of this guide.

The last stretch

Hope that was a fun experience!

Now you'll need to download the latest LSPosed release (Get the Zygisk release as Riru is deprecated). Put the zip somewhere on the phone and install it through Magisk and reboot.

Next install FakeGapps, and enable it in LSPosed and reboot. Then go into LSPosed modules and in FakeGApps you will need to enable all the relevant apps for location (i.e. MicroG, your location back ends, and your maps apps).

And now, same as last time just wait and check. If it does not work, tweak some settings and see if there's any troubleshooting you can do.

This should just work, MicroG should be able to fully masquerade as google play and be able to provide the necessary location data.

There may be more troubleshooting you can try, but this is where it finally started to work for me.

Rooting

If you are not familiar with rooting, keep in mind that if you are not careful you will brick your device. Do your own research, make sure you actually know what you're doing, and consider if you actually need to bother going through the process in the first place.

To preface, the 90XKC cannot be rooted, but the KY-42C and the A20XKC can be. This is due to the Mediatek CPU that these phones feature. It's been a while now since I rooted the phone so I forget some of the issues I faced, so instead I'll leave some tips from what I recall and I'll update this section if someone leaves a comment on the subject.

This is not a guide on how to root the phone, just some pointers on issues I faced, our experiences will differ regardless.

If you have a Linux OS this process will be a lot easier then doing it on windows, I tried going through the process on windows but ended up giving up and switching to Linux.

To root the phone and unlock the bootloader we will use MTKclient. If you are on a Ubuntu distribution of Linux there is also Live DVD 6 as an alternative. I just used MTKclient but this person has used both with the KC-42C and I'll link their experience here.

Just follow the steps on the MTKclient Github to install and run it, this section will just be for specific tips that may be helpful during the process.

When attempting to "build the wheel" on windows I had errors, there is a section on troubleshooting this on the page but some of it seemed to be outdated as well. It's been a while since I rooted the device now but I believe I found this thread to be useful. Also scroll through the issues section of the Github to see if anyone has already mentioned the issue you have. If you have trouble getting it running then also feel free to leave a comment about the issue as I'm probably forgetting what issues I faced (which are probably the same as yours).

I also was having issues running ADB as root on the device, there are some Magisk modules for this but I don't believe that these helped in my case. I recall finding some resources on it and ended up being able to enable shell as root in Magisk which fixed the issue. Let me know if you have this issue and if you solved it and I'll add it in here.

Misc/Tips

Audio

Bluetooth on these phones just work. It supports the Bluetooth controls flawlessly even when the phone is closed. I have the Sennheiser Momentum 4 headphones and can switch songs, change volume, and modify my noise cancelling perfectly fine.

The USB C port can be used for audio but only works for some cables. The port only supports audio through something called passthrough, which basically just means it only supports USB C cable with no DAC (Digital Analog Converter). This is the same for the Moto Z, and Motorola makes a cable for their phone to address this. Most cables won't mention passthrough, but the biggest thing to keep a lookout for is whether they advertise it having a DAC or not. You can also take a look to see if they mention that they specifically support the Moto Z or another phone with this same requirement.

Charging Cradle

Thanks to salyrus for this info
There is a charging cradle that works for both of these phones. The cradle is made for the KY-41B but is the same dimensions so it works for these phones as well, This cradle only comes in white and is strictly for charging.

Sub Display Date Tweak

(Thanks to HogwashDrinker)

If you go to the sub display settings and put it to small it will add the date to the display.

Updating
These phones update using OTA (Over the air). You cannot update them outside of Japan. I've tried a VPN and had no luck with that either. Also you may need to have an active usim from Softbank/Y!mobile in order to receive the updates even if you were in japan. I do not know much about how that works however and it seems to contradict information from Softbanks update page.

Troubleshooting

SIM Locked

If you forgot to check if it was unlocked first, or if you got unlucky and it was mislabelled then there are ways to unlock the phone still.

Step by step guide:

• Book a flight to japan
• Speed learn Japanese on the plane
• Go to Softbank/Y!Mobile
• Ask really nicely for them to unlock it for you
• Profit

If you cannot speak Japanese, or more likely if you are as broke as I am then there is a cheaper but much sketchier option. I will link it here for you to check out but I have no experience going through the process personally and you should really research it yourself if you are faced with this issue. Although a youtuber I saw named F4mi did say that it worked for her.

I LOCKED MYSELF OUT OH GOD HELP

I actually faced this issue because I made the mistake of setting KeyMapper to the default keyboard. Thankfully, if you have your phone set to "Always allow connection" you can just plug it into the permitted computer and change the keyboard to the default or TT9.

In the terminal:

adb shell
ime set io.github.sspanak.tt9/.ime.TraditionalT9

Alternatively if you can't use TT9 for some reason, you can reset the keyboard to the default:

adb shell
ime reset

I'm stuck in infinite bootloop hell

I haven't faced this personally, but here are some threads with people that went through a similar issue:

https://www.reddit.com/r/dumbphones/comments/184f2jm/comment/mf7janb/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

Opening Dev Options crashes Settings

Had this weird issue after rooting the phone and re-flashing, this thread fixed it for me.

Fossify Contacts won't share contacts to other apps

Weird issue with this one, Fossify contacts does not make its own contacts directory, and because of that you need to make it with another app. I believe that you can do this with the stock contacts app but an easier solution for me has been installing this alternative FOSS contacts app. Just import all your contacts into it, download Fossify Contacts, and then delete the alternative contacts app. Fossify will now continue to use the new folder and share contacts to the other apps.

Resources

Digino User Guides:

A20XKC
90XKC

Kyocera Open Sourced Builds:

http://android-dev.kyocera.co.jp/source/source.html

I have not heard of anyone successfully using these files to update the phone, and I have heard that a "Factory Signature" may be required and that the phone would not boot properly from a boot that you created