Anime News Network (by way of Sankei News) reports that Akira Toriyama himself sketched Ayumi Hamasaki as “Goku” for her CD single release of “Rule” (the international theme song for Dragon Ball Evolution):

This is the first time that Toriyama is responsible for this type of music-related release. The first pressing of the release will have these sketches, though there is no confirmation on whether or not it will resurface down the line for additional pressings of the CD.

We have the CD+DVD combo on pre-order, and will be reviewing the entire package once it comes in. It all drops 25 February 2009 in Japan.