To use Kaerutomo on Android, you will need a device running Android 4.1 or higher with an ARM-compatible processor and at least 512MB RAM; these are the same system requirements as Miitomo originally had, so if Miitomo will launch on your device, you should be able to use Kaerutomo, too.


If you are using an Apple device, instead see the following guide: https://kaeruworld.freshdesk.com/en/support/solutions/articles/33000254520-kaerutomo-setup-instructions-for-ios


You will also need to have a legitimate copy of the latest version of Miitomo, downloaded from the Play Store. Unfortunately Nintendo no longer allows you to add Miitomo to your account, but if you had downloaded it before the shutdown, you should be able to redownload it here: https://play.google.com/store/apps/details?id=com.nintendo.zaaa


Whilst we won't go into specifics, some people have had success using Kaerutomo on emulators such as Bluestacks; the process is largely the same as for real devices, but make sure that you sign in to and launch Google Play before launching Miitomo, as otherwise you may encounter error code 801-1350-2407.


Enable sideloading


Firstly, you may need to enable 'unknown sources' in your device's security settings. If your device runs Android 7 or lower, open the Settings app and look for a submenu named 'Security' or similar, then toggle on 'Unknown sources'. This will allow you to eventually install a modified Miitomo APK file, once you've patched it.


On devices running newer versions of Android, you may instead be asked to grant permission to an app to install unknown apps from that source; do so when prompted.


Once you have finished, you can safely disable unknown sources again to keep your device secure, as this does not erase sideloaded apps that have already been installed.


Download necessary files


Kaerutomo patch bundle


To get started, you'll need to download the Kaerutomo Anniversary Release patch bundle: https://kaeru.world/go/tomoannivdroid


If you have been granted access to the Kaerutomo Private Beta service, instead download the Kaerutomo Private Beta patch bundle (note that this is by invitation-only to donators and Patreon supporters).


(If you have been invited to the Kaerutomo Private Beta, please see the instructions available in the #miitomo-beta-info channel within our Discord guild for the required patch bundle and alternative instructions, since it's all in flux at the moment.)


Only download one or the other; if in doubt, download the Anniversary patch bundle.


These bundles contain Xdelta3 / VCDIFF format patch files for various binaries within the Miitomo app, along with a replacement npf.json configuration file which you'll inject into Miitomo to access the Kaerutomo server.


Once you've downloaded it, extract it somewhere on your device's storage where you'll be able to find the contents later.


Apps to patch APKs


Next, you will need to download and install two apps: APK Editor (com.gmail.heagoo.apkeditor) and UniPatcher (org.emunix.unipatcher).


UniPatcher can be found on the Play Store at https://play.google.com/store/apps/details?id=org.emunix.unipatcher; however, APK Editor has unfortunately been removed due to changes in Google policy, so you will have to find this yourself online. We cannot help you with this, but take care to ensure that you download APK Editor, not APK Parser, as the latter does not include the necessary functionality.


Note: Although Unipatcher works for most people with no problems, some people have had issues with it, especially on older devices. If you receive Unipatcher errors, make sure you have selected the correct files and that it has all necessary permissions (such as 'read/write storage'). If issues persist, contact our support team for help; you can also try using an alternative patching progam, 'ROM Patcher', although this is no longer available in the Play Store.


Extract Miitomo binary files


Using APK Editor


We will be using APK Editor to unpack and reconstruct the Miitomo app file. Here's a quick overview of how to use it:

  • To open an app in APK Editor, select either 'Select APK from App' to start with an installed app, or 'Select an APK File' to select an APK file from your internal storage.
    You'll probably want to use 'Select APK from App' if you've installed Miitomo from the Play Store (remember that Kaeru Team can't offer help for pirated copies due to the wide range of variables involved).
  • For Kaerutomo, we only need to do a 'Simple Edit' (file replacement), so make sure to choose this option.
  • To navigate into a folder, simply touch the folder name, and to go back up a level, touch the '..' option.
  • To extract a file, touch the 'save' icon next to it, then select a save destination.
  • To replace a file, touch the 'pencil' / 'notepad' icon next to it, then select the replacement file.
    Note that the new file will be renamed to match the one you're replacing within the app, so the filename doesn't really matter.
  • To save a modified app, tap the 'Save' option at the bottom of the screen.


Extract Miitomo files

  • Open APK Editor and select a clean (unpatched) Miitomo 2.4.0 APK file - you should dump this yourself, as it's not legal to share this.
  • Extract the following files from the Miitomo app, as described above - save these somewhere that you'll remember, since you'll need them again in a moment:
    • classes.dex
    • lib/armeabi-v7a/libcocos2dcpp.so
    • lib/armeabi-v7a/libsakasho.so (only for Kaerutomo Beta)


Patch extracted files

Using UniPatcher


We will be using UniPatcher to apply the Kaerutomo patches to the Miitomo binaries. It's rather intuitive so probably doesn't need much explanation, but to summarise:

  • Under 'Patch file', tap the button select the appropriate Xdelta patch file from our patches bundle.
  • Under 'ROM file', select the file to patch. (It doesn't matter that we're dealing with app components rather than a game ROM, as it works the same.)
  • Under 'Output file', choose a sensible output filename, e.g adding 'patched' to the filename (which it will do automatically for you) -- the patched file will be saved in the same directory as the source binary.
    It doesn't matter what you name the output file or where you put it, so long as you can find it again later.
  • Tap the floating Save button to the patched file.


Patch the Miitomo binaries


Open UniPatcher and patch the following files with the following patches:


Binary file ('ROM file')Patch file
classes.dexclasses-kaerutomo-anniversary.xdelta (Anniversary); or
classes-kaerutomo-beta.xdelta (Kaerutomo Beta)
Do not use both, this will not work correctly.
libcocos2d.so (lib/armeabi-v7a/libcocos2d.so)libcocos2d.xdelta


If you have been given access to the private Kaerutomo Beta service, also patch this file (most people do not need to do this):


Binary file ('ROM file')Patch file
libsakasho.so (lib/armeabi-v7a/libsakasho.so; only for Kaerutomo Beta)libsakasho.xdelta


Inject patched files


Finally, return to APK Editor, load in Miitomo again if necessary, and replace the files shown in the table above with your patched versions, as explained in the 'Using APK Editor' section.


Once you have replaced those files, there is one more step - within the assets folder, you will need to replace the npf.json file in your Miitomo app with the file of the same name from the Kaerutomo patch bundle downloaded earlier. We replace this file entirely, so there is no need to process it with UniPatcher first.


Finally, save the modified Miitomo APK using the button at the bottom of the screen.


Install your patched Miitomo APK


You've finished the patching process; the last step is to uninstall Miitomo on your device, if it is already installed, then reinstall it using your patched Miitomo APK. These last steps can be done from within APK Editor using the buttons provided (touch 'Remove' and then touch 'Install' -- if the install stage doesn't work, go to /ApkEditor/tmp in a file browser and touch 'gen_signed.apk' to install it).


Next steps


Before using Kaerutomo for the first time, we recommend you read and bookmark the Kaerutomo Post-Install Guide, which covers some important notes and explains some common error messages: https://kaeruworld.freshdesk.com/en/support/solutions/articles/33000254535-kaerutomo-post-install-guide-common-errors