Yes, you heard it correctly, Lenovo is trying its hand at a Windows 10 smartphone. But, before you get too excited, it really seems like a one-time deal and chances are it won't be available at your local electronics store. The name mostly gives that away. Really, what is happening here is that the Japanese carrier SoftBank has tasked Lenovo with creating a phone to add to their existing lineup of handsets. And it just so happens that the phone they requested had to be one running Microsoft's mobile OS. That being said, since the 503VL is a carrier device, it is exclusive to Japan...
Source: http://www.gsmarena.com/lenovo_just_announced_its_first_windows_10_phone__the_softbank_503vl-news-19430.php