Shizuku is an application that acts as ADB connector, for other applications allowing them to use elevated privilege to perform actions normally blocked by the Android OS

For our purpose, Shizuku’s ADB permissions was used to edit android/data directory

In summary our method is to use Shizuku to rename the package directory and perform “clear all data” to evict any account information, before renaming it back again, to avoid re downloading all game data every time we reroll our account

I promised I would make a proper guide someday but I found out by random chance, that google have already killed ADB access to android/data in Android 15

That said apparently the native file app with package ID com.google.android.documentsui still can access Android/data/ directory, though it cannot edit files it can rename it, which might serve as a method to still do this, but now every new cloned instance requires its own data download

Well then that didn’t happen so here lies that method, obsolete for these above Android 15, pasted as is from discord:

for anyone doing rerolls to help other do the friend mission
android rerolling without deleting app every time is still possible
general guide still hold true https://www.reddit.com/r/ProjectSekai/comments/rbflyp/reroll_guide_for_android/
in step 3, modern android have some security measure to stop normal apps from accessing /storage/emulated/0/Android/data directory
currently adb still can access the Android/data directory
shizuku pairs with your android system via wireless debugging granting itself special adb permissions and acts as a platform for other apps to execute actions that require adb permissions
you can use a shizuku capable file manager to access the Android/data directory and rename the app data file so you dont have to keep redownloading all the data everytime

Basically setup shizuku, use your choice of file manager that supports shizuku and follow the guide as usual

shizuku https://shizuku.rikka.app/
shizuku capable file managers https://github.com/timschneeb/awesome-shizuku#file-management
(personally i used X-Plore)
this is not a question, this is posted as information for anyone who happens to search about how to re roll an account without deleting all the data