While the internals (Snapdragon 820, 3GB RAM, 5.2-inch 1080p display) are identical to the global variant, the modem, bootloader, and partition layout are distinctly different. The firmware includes specific carrier aggregations (for LTE bands 1, 19, 21, and 28), Osifu-Keitai security protocols, and Japanese-exclusive features like POBox Plus (a Japanese input keyboard) and 1-Seg mobile TV support.
Download the official SO-01J stock ROM FTF file from a verified repository or via the tool.
Clean install if the device is sluggish or infested with errors.
Launch (use the 64-bit version if running a 64-bit operating system).
Once Flashtool detects the green LED connection, it will automatically start flashing the stock ROM. Release the Volume Down button. Official Sony Xperia XZ SO-01J -Docomo Japan- Stock Rom
You will need to download three essential components onto your Windows PC:
What (Oreo, Nougat, Marshmallow) do you want to install?
No. Flashing the official NTT Docomo Stock ROM will not bypass a hardware-level network lock. To use a non-Docomo SIM card, you must obtain an official network unlock code directly from the carrier. Can I flash global Xperia XZ (F8331) firmware onto the
Before downloading any files, verify that your device matches these exact specifications to avoid permanently damaging (bricking) your hardware. Sony Xperia XZ Model Number: SO-01J Carrier: NTT Docomo (Japan) Chipset: Qualcomm Snapdragon 820 While the internals (Snapdragon 820, 3GB RAM, 5
Locate and download the specific from a trusted archive or use XperiFirm (integrated into Flashtool) to fetch it directly from Sony/Docomo servers. Step 2: Prepare the Firmware File
Once complete, unplug the device and power it on. The first boot can take 5–10 minutes. Important Considerations for Docomo Devices
Deep integration with Sony’s "Mora" service, providing access to a massive library of high-resolution audio files critical to the Japanese audiophile community. Docomo Palette UI:
Version 41.3.B.1.140 (common for later updates). Clean install if the device is sluggish or
Ensure your Xperia XZ has at least 50% battery capacity. A sudden power loss mid-flash will corrupt the partition table of your device. 3. Install Device Drivers
Before selling your used SO-01J, you should flash the stock ROM to wipe all personal data completely and restore carrier demo modes (if applicable).
The official Sony Xperia XZ SO-01J Docomo stock ROM is the safest and most stable firmware for Japanese variant users. Whether recovering a bricked device or restoring factory condition, always flash the correct build for your model to avoid radio or performance issues.