This is a reference track for a sheet music of "AAIO". 

It's made by Ryota Nozaki as a solo piano arranged version of "Nanairo", which is known as one of popular songs of Jazztronik.

This track hasn't been released digitally like on CD, streaming etc.

It's only available in an accompanying CD of the sheet music of "AAIO" and also has other 2 tracks(only Beat, karaoke for piano) in it. 

You can buy the sheet music on Jazztronik web store. https://jazztronik.stores.jp/