Sony's Xperia Z3+ release schedule has just been announced. In June 2015, the device is exclusively going on sale in Japan where it is being called the Z4. The exact release date for the international Xperia Z3+ is still pending. In the meantime, Sony has confirmed that Android 5.1 Lollipop is coming to both the Xperia Z3 and Xperia Z2.

Xperia Z4 is Now the Xperia Z3+

The Xperia Z3+ was originally dubbed the Z4, but Sony has apparently changed its mind. Only the Japanese model will be called the Z4, while all other versions will receive the Z3+ designation.

"The main reason for the name difference here is down to Sony being such a dominant force in the Japanese market [where] consumers crave flagship devices with the latest features as soon as they can be delivered," Sony said, according to the Inquirer.

"Xperia Z3 continues to perform well as our flagship device across the rest of the world. To address those customers that would like to have the very latest features and refinements, we have introduced Xperia Z3+ as a premium addition to our existing flagship Z3 series."

Like the Xperia Z3, the Xperia Z3+ sports a 5.2-inch LCD display with 1080p resolution. Materials used in the smartphone's construction include high-end aluminum and glass.

"However, the design will be further simplified and even more seamless, with less covers and less seams on the frames," Sony added.

Admittedly, the Z3+ is Sony's lightest and thinnest Xperia Z series smartphone to date. In fact, the device weighs in at just 144g, and is 6.9mm thick. Out of box, the Xperia Z3+ runs on Android 5.0 Lollipop. The Xperia Z3+, or Xperia Z4, will ship out to stores starting this summer.

All Sony Xperia Z Series Devices Will Receive Android 5.1 Lollipop

Earlier this month, Sony confirmed that it is updating every one of its Xperia Z series devices with Android 5.1 Lollipop. This move is a follow-up to the previous mass Android 5.0 Lollipop update that ushered the end of the Android KitKat era for the Xperia Z series.

According the official Sony Mobile blog, the Android 5.1 Lollipop update is rolling out in July. Naturally, users with unlocked devices will receive the update first. Those who are on Verizon, Sprint, AT&T, and T-Mobile subscription plan will need to wait a little longer. Generally, it takes awhile for carriers to distribute the latest Android update from the manufacturers.

Here is Sony's changelog for Android 5.1 Lollipop:

• Fresh, streamlined looks - based on Google's material design, but retaining our minimalistic approach to interface and application design

• New look notifications and lock screen - with fully customizable settings, so you only get the information you really need

• Multi-user profiles and guest mode - making it easy for family and friends to use your device, or the creation of dual environments for work and play...

• Android for Work - not only are business-ready Xperia smartphones and tablets unique devices for work - with waterproof form factors, great battery life and productivity features - they will now also be part of the Android for Work ecosystem

• Better storage control and customization - with the option to easily move applications from internal memory to SD card - giving you more control over your content, particularly useful for devices with slightly less space