I actually think this might be another mini album, containing more than one song, with 20 different versions. The product code is HWCT-0006. If you look at all the other discs he has released with the HWCT code, then you will find all of them have at least five different songs on them. The other singles, such as Earth in the Dark and 大切なもの come with the code HWTS.
Looking at it, he has いつまでも, 変わらない真実 (recent single containing Itsumademo and the new duet, ありがとうのうた (the song Arigatou no uta originally released on the HW-CH music site as a Toshi with T-Gaia track) and also the title song, 地球まだありますか (sung at the recent concerts, included on the Toshi and Wanku night DVD), all yet to be released on an album. So that is four songs already, definately reaching up there with his using number of tracks.
Well, that's my guess. Either way, I enjoy all of Toshi's solo music and am eager to get hold of a new album, (buying all the singles that he releases is a bit too much for me ><)