The immediate conclusion when you think of Assassins Creed in Japan, is the guy should be a Ninja. Because they're agile and do assassinations in stealth, but ultimately i liked the samurai concept better. It has more to work with than a simple ninja outfit.
A friend said, how would a samurai do free running with all the armor on them... In which i replied, How did Altair and Ezio do free running with all that stuff on them too. Seriously. Ezio in AC2 had crazy amounts of Metal Armor, swords, smoke bombs, daggers and crossbows all over his body, yet he's the Ninja of the Europe. lol
Anyways, i'm going to tune the concept some more and then, when i get my new baby, do a 3d model of the character. Its gonna be sweeeeeeeeeeeeeeeeeeeeet!