DAIGO's K S K ~W Version~ is now available digitally on Recochoku from 20th May (midnight) until 14th June (11.59pm) . {both timings are in Japan time}
This version might not be the same as the version/s that will be included in next month / 15th June's release of K S K .
I think this version is the 1 that was released in the CD that DAIGO & Kitagawa Keiko gifted to 500 guests who attended their wedding ceremony/reception last month .
Seeing that the cover used on Recochoku is this one
http://recochoku.jp/song/S1003239203/
Also during the same limited time frame period , for purchase of , buyers will receive a free DAIGO "Kumapanda W ver." Wallpaper too
https://recochoku.jp/lapap/tokuteninfo/20001877/