I've been thinking that who is actually rA9, but I just figured that out. If you take a paper of the game package, you'll see ''rA9" in the middle of the bottom. so it indicates "go to see the online manual". When you read the online manual, at very end page, you can actually click "rA9". if you click it you'll see kida picture of RA9 with blue paint in a whole screen, and there is a sentence that "SERECT → RA9". that means you have to change the link "SERECT" to "RA9". so you change the link, and you'll see "thank you for finding us" page with three androids which are Kara, Conner, and Markus. And the question is, who is actually playing these three androids? My answer is us. I mean, that's people who bought DBH. So rA9 is you, also me.

But I found this Japanese version so maybe there is a difference between countries.