This is the latest in a line of Koei titles where they have used the same group of voice actors. This started with Kessen II, then continued with Dynasty Warriors 4, Dynasty Tactics 2, and Dynasty Warriors 4 Xtreme Legends.
Bonus characters will become available in Kessen III if a player has save data from either this game or its expansion, Samurai Warriors: Xtreme Legends, and uploads it into a Kessen III save file.