Joined this forum just to make a half-assed contribution to this thread.
I've been toying with the idea of a Sailor Senshi class in the back of my mind for some time. It's a pity I don't still have the 3.0 class creator formulas I had ages ago or I would hammer it out. Of course, Senshi seem to prefer to only work together, so a Sailor Senshi campaign might be repetitive or shallow.
I see a Sailor Senshi as a sort of a divine Sorcerer or a boarderline Witch. A character with a Cleric domain (or two or three, maybe as they level) who would get the benefits of that domain(s), only be able to cast spells spontaneously from their domain(s), and cast them a large number of times. Perhaps there would be a 'Fighter' class with the good BAB, a 'Healer' class with the average and a 'Maker' class with the worst, and other appropriate adjustments to ability, hit dice, and access to free feats. Certainly it should be highly customizable, as there are so many vastly different Senshi.
I wonder if I have that anime d20 pdf lying somewhere still so I could cannibalize the Magical Girl class..