NTT Docomo is Japan’s largest mobile carrier. Their devices are known for high-quality hardware but come with strict software limitations. Docomo heavily modifies its Android firmware, packs it with carrier bloatware, and intentionally blocks official bootloader unlocking methods.
Before attempting to unlock the bootloader on a Docomo device, make sure you have the following:
You may use the UnlockBootloader command via the Odin tool or rely on the download mode on-screen instructions to confirm the unlock using the Long Press (Volume Up) method. docomo unlock bootloader install
Some custom ROMs require specific flashing patches or IMS registration edits to enable Voice over LTE (VoLTE) calling on the Docomo network. Check your ROM’s specific device thread for a VoLTE patch if your calls fail to connect.
This approach is not recommended for most users, as no consistent success has been documented. NTT Docomo is Japan’s largest mobile carrier
Note: The exact tool depends on your phone model. This example outlines the exploit-based method commonly used for carrier-restricted devices.
Let’s assume you own a (Xperia 1 II). This is one of the easiest Docomo phones to unlock. Before attempting to unlock the bootloader on a
Docomo phones are historically difficult to unlock. As of 2026, many older "free" exploits are patched.
It is critical to distinguish between these two. A SIM Unlock (performed for free via My docomo as of October 2023) only allows you to use other carrier SIM cards. It does not unlock the bootloader for custom ROM installation. Step 1: Preliminary Requirements
Step 4 — Root / custom ROM / firmware install
Type: fastboot flashing unlock Note: If this command fails, try fastboot oem unlock .