Oh, thanks for catching that
4. ちいさい秋みつけた (chiisai aki mitsuketa)
I wonder if the only way to get the CD is to be physically in Japan...
There must be some way to get it using fromjapan.co.jp - if I'd been alert at the time I could have bought more copies to share around. I could ask Kaori Hikita on twitter or if you are on Facebook you could ask her that way.