I noticed this too, when I was living in Japan as an exchange student. I ran a 2E game (circa 1995) with a very basic plot--gnolls were attacking outlying farms, and the characters were in the farming villages trying to hold them back until the army could be raised to deal with the threat. My Japanese friends were all about defending their homes and taking huge personal risks to defend the community, but the social expectations were different.
To me, the most striking difference was that some of the players were very concerned about their obligations to the community, whether it was to their own family or the local nobles. One player went to painstaking efforts to detail how he made sure that his parents were provided for before striking out for a life of adventure, regularly sending them money and visiting as soon as the current adventure was concluded. Two others actually sought permission from the elders of their families to go on adventures. Another wanted to make certain that the local feudal lord knew exactly what they were up to and kept meticulous records of the party's activities.
Playing Sword World RPG was a hoot. We played a group of adventurers that sailed the fringes of a big ocean fighting pirates along the way. Although we were fighting pirates, we never kept any of the loot--it was all turned over to the authorities, and we got our treasure from them as reward for a job well done. That was certainly different to me.
I tried getting those guys into a Vampire: the Masquerade game but it just didn't pan out. They had no interest in playing monsters or dealing with horror themes.
I only played with this one group while I was there, so I have no idea if the group just liked heroics or it's more representative of the culture. Still, these cultural differences took more getting used to than the language.
Back in the states, I played with Japanese exchange students when I could. They enjoyed the 2E game that I ran and gave Mage: the Ascension a shot, even though I think that game was a poor choice in retrospect because of the language differences--it took a lot of discussion to get across some of the concepts of Mage. But then again, it usually does for a group of native English-speakers as well.
