Although the Xperia Z series is no more, Sony delivered on its promise to update the Z5 line to Marshmallow. Sony has started seeding the Android 6.0 update to Xperia Z5, Z5 Compact, and Z5 Premium units on Japanese carrier DoCoMo's Network. There's no info on when the update will be broadcast outside Japan, or when it will be reaching unlocked units. However, Sony has published screenshots and details on at least 20 additions contained in the Marshmallow update.
This is a pretty big one, Z5 owners, so be ready for some welcome changes and improvements across the board! You can learn more about the changelog in the slideshow below. Thanks to /r/Android's trinitynox and PeanutButterChicken for the English translation!
Changes in the Xperia Z5 update to Marshmallow