I think it wouldbe incredibly close both have their pros and cons, they are fast, have good sense, and good with their swords.
i think in the end it would be kenshin who won, becuz, of the style of fighting he uses, he could predicte inu's next move and be one up on him. plus inu can be a little too agressive with his fighting, he gets angry and fustrated quickly and kenshin would be able to see his emotions and breakdown points. although inu isn't completely mortal so it would be harder for kenshin to completely break him down. I havent seen all of the inu infact in not to far, they only hve half the jewel shard so there could be factors that i'm missing, but my idea still stands, kenshin would win.
thouht it would be interesting since they are my two favorite animes and charries.
