There's multiple reasons why I'm buying the single...to support ayu's 10th anniversary, I buy her singles normally, mirrorcle world (the song) is just awesome!, special version of old songs, the covers are very beautiful, the special packaging, etc
I just think this release in general is very special in many ways so instead of buying 2 versions, I'm getting all 4.
I voted for ayu's 10th anniversary...its the closest I guess.