For anyone having trouble backing up their FGO save data or playing the same account on multiple devices because of Android's restrictions on the Android/data folder, I found a relatively simple workaround.

Important: This method only works for transferring/syncing data between an Android phone/tablet and an Android emulator on PC.

This guide is based on the method described in the original post:

https://www.reddit.com/r/grandorder/comments/hfbz0h/fgo_save_files_for_na_and_jp_play_on_multiple/

Transferring the save data from an emulator to a phone was troublesome for me. It required root access and several different apps, and even then, I couldn't get it to work reliably.

So instead, we're going to do the same process in reverse:

Set up FGO normally on your phone/tablet → copy the save files → transfer them to your PC → replace the files in the emulator.

The important part is that the Android file restrictions that prevent you from properly pasting files into Android/data on a phone don't apply in the same way on an emulator.

Step 1: Copy the save files from your Android device

Download Marc Files on your Android phone or tablet:

https://play.google.com/store/apps/details?id=com.marc.files

Using this file manager, navigate to:

Android > data > com.aniplex.fategrandorder.en > files > Data

Find these four files:

54cc790...
64b05...
969b465...
e1a9f8...
Select all four files and choose "Copy to".

Copy them to a normal, unrestricted folder, such as:

Downloads

Transfer the files to your PC

You can now transfer the four files to your PC using email, a messaging app, cloud storage, USB, etc.

Alternatively, you can skip the file manager entirely:

Connect your phone directly to your PC and browse to:

Android > data > com.aniplex.fategrandorder.en > files > Data

Copy the four files directly to your desktop.

Step 2: Prepare your emulator

Open the Android emulator you want to use.

I personally used MuMu Player, and I can confirm that this method works with it.

Open your PC's Documents folder and navigate to:

MuMuSharedFolder > Download

Place the four save files you copied from your phone into this folder.

Step 3: Install and start FGO on the emulator

Download and install FGO on the emulator.

If you already have FGO installed, clear its cache and storage and redownload the game to make sure you're starting with a clean installation.

Open FGO and go through the initial setup.

Select your region and let the game start.

Once you reach the beginning of the main story and the "Skip" button appears, close the game.

At this point, the game should have created the necessary folders and files on the emulator.

Step 4: Replace the emulator's save files

Open the File Manager inside MuMu Player.

Navigate to the Download folder and find the four save files you placed there.

Select all four files and right-click → Copy.

Now click the three-line menu in the top-right corner and switch from MuMu Shared Folder to your emulator's internal/phone storage.

Navigate to:

Android > data > com.aniplex.fategrandorder.en > files > Data

You should see the same four files that FGO created:

54cc790...
64b05...
969b465...
e1a9f8...

Delete those four existing files.

Then right-click → Paste to put the four files you copied from your phone into this folder.

Step 5: Start FGO

Open FGO again.

If the game says that you are currently "in a quest", simply select "Abort".

Your account/save data should now be loaded on the emulator.

Why does this work?

The main problem is Android's restrictions on the Android/data folder.

On a modern Android phone, you generally can't freely copy and paste files into an app's Android/data directory. Even when using a file manager, the "Copy to" function does not allow you to navigate into the FGO folder.

The emulator is different because you can access its internal storage through the emulator's file manager and use normal Copy → Paste operations.

So instead of trying to:

Emulator → Phone

we do:

Phone → PC → Emulator

The phone is only used to obtain the save files, while the emulator handles the final file replacement.

I don't know how many people are struggling with this issue, and there may be other solutions that I'm not aware of. Personally, I couldn't find a reliable solution, so I decided to try reversing the process instead.

Now that I know it works, I hope this post can help others who run into similar issues in the future.