Discuss all things Saikano... well, just don't get too far off topic :) btw, this board won't refresh automatically(hey, it's free), so make sure you refresh it after you post any new messages.
Well, I think it could be Kanashami no Nukumori, as well as Hoshi no Hate. Either way, both of them are included in the OST. Hope I helped you.
Thanks guys, found it.