To fix this, flash via your custom recovery to root your device.
Flash custom ROM, GApps (if needed), Magisk (for root), and firmware patches:
Execute the following command to boot your phone into its low-level flashing environment: adb reboot bootloader Use code with caution.
Before flashing anything custom, . The TA (Trim Area) partition contains your device's unique DRM keys for camera processing (low‑light enhancement, noise reduction) and other proprietary features like BIONZ for Xperia.
The phone will display a warning message. Use the volume keys to navigate and the power button to confirm. The device will then perform a factory reset and reboot.
Docomo devices use a specialized hardware chip for Japanese mobile payments (FeliCa). Unlocking the bootloader or flashing a non-Japanese custom ROM often breaks this functionality permanently.
(Note: For modern devices using a virtual A/B partition system, you may need to boot the recovery temporarily instead: fastboot boot recovery.img and then install it permanently from within the recovery interface). 6. Step 4: Installing a Custom ROM
This official process on DOCOMO devices because Sony explicitly excludes carrier variants from the program. If you attempt it, the command will simply fail.
This comprehensive guide breaks down the reality of the process, providing clear steps, explaining critical technical limitations, and detailing alternative solutions.
