Yes, there is a Rurouni Kenshin RPG.
I forgot the title, but it's for the PS1, not the PS2. I got mine on Ebay for $50, brand-new from Japan, and the game is really fun and
kawaii!
However, since I don't understand Japanese, it's really hard to follow the plot and directions. The characters are Kenshin (duh), Sano, Kaoru, and Yahiko. They help out the two new characters in the game, a guy and girl who are on a mission....to..uh....do something.
There are separate stories for the guy and girl, and if you pick the girl, Kaoru and Yahiko help, and if you pick the guy, Kenshin and Sano helps out. It's really fun, and it kinda reminds me of Tales of Destiny (if you've ever played that). But, I don't know if you can still get it.....you should try Ebay, because I think some people still sell it. I hope this helps.