No, it’s not the official image album nor the OST. This is just a doujin image album by Voltage of Imagination which started way back 2008 at the C74 up to C76 in 2009. The author himself is not involved in it too. Anyway, there are 4 albums: GET SET, AHEAD, BREAK and GO AHEAD. onoken provided the music while Chata, Aki Misawa and Rekka Katakiri provided the vocals.
It’s English title is “The Ending Chronicle“. It’s a light novel written by Minoru Kawakami and it’s illustrated by Satoyasu. Actually, there is NO English translation of this. But I’ve heard that there’s a drama CD version of it. And so far, no manga and anime version of it yet.