Below are links to two galleries online with a selection of his storyboard works;
http://videogamesdensetsu.tumblr.com/po ... バースターストーリー
Of particular interest are some of the really out there ideas that were likely held back due to limitations of the hardware and, I'm guessing, time. The very first image for example shows what appears to be a pod-race type scenario that has some striking similarity to the air bike service tunnel chase scenes from Akira. I particularly like that it's Mia piloting it alongside Alex, suggesting it's later in the story (aside from the obvious Dragonmaster regalia).
![Image](https://78.media.tumblr.com/18f1fb13d0008de6599f110134734959/tumblr_oh0kts0Urd1ulp8mfo4_1280.jpg)
Or how about Alex, Luna, and Nall escaping pirates aboard a small air ship?
![Image](https://78.media.tumblr.com/0964195957f73a61b315be3d0ee02397/tumblr_oh0kts0Urd1ulp8mfo5_1280.jpg)
![Image](https://78.media.tumblr.com/b82cc6265facd4a52725d87756876ead/tumblr_oh0kts0Urd1ulp8mfo7_1280.jpg)
I thought this particular image is interesting as it appears to possibly be an alternative form of one of the dragons, yet if you look closely in addition to books there are old computers strewn about.
![Image](https://78.media.tumblr.com/152933dd783d69088b8513b370c2ef23/tumblr_oh0kt2kFrc1ulp8mfo2_1280.jpg)
![Image](https://78.media.tumblr.com/da463322149728c8b3274d974c09b8a3/tumblr_oh0kt2kFrc1ulp8mfo1_1280.jpg)