On this page, you can find the official KDDI Optimus G LGL21 USB Driver, which allows you to connect the device during the flashing process or while generally connecting the device to the computer.
There is one driver available for the device, i.e., ADB Driver. The ADB Driver supports Flash Tool and IMEI Write Tool and can be used for Firmware Flashing or IMEI writing.
The ADB Driver is required if you want to perform the ADB debugging with the Android Devices.
Driver Name: ADB Driver
Package Name: usb_driver_r13-windows.zip
Driver Size: 8.27 MB
How to Install: Follow Guidelines
[*] Driver Signature Error: If you are facing Driver Signature Error While installing the driver on the Windows Computer, then to fix the issue follow How to Fix Driver Signature Error page.
[*] Driver Easy: If you are still facing issues with the USB Driver, then we recommend you to use Driver Easy Application to Search and install the required drivers automatically.
[*] KDDI Optimus G LGL21 Stock Firmware: If you are looking for the Stock Firmware, then head over to the Stock Firmware page.