I'm a game development student here in Tokyo. I've been living here for 2 years now and am actually thinking of going for US instead. Anyway, although this is just an anecdote and not from a source with statistical evidence (since I just asked my Japanese classmates), I would just like to share what they said.
The Steam store itself is too dark. They said the Japanese love colorful stuff and that the Steam store is too dark for them. I guess if you compare Steam to other DD services it is dark but I just like the way it is because it seems elegant.
The prices aren't in Japanese Yen. They have to bother calculating the US dollar to Yen. I agree with this. Other stores like Play-Asia have the options of seeing prices in different currencies. Steam should do the same.
It isn't in Japanese. Most of them they say take a while to read English and it would have been great if it were in Japanese. I have no problem with English since it's my second language but I understood what they felt when I opened Origins here in Japan and it was in Japanese. I still wasn't as good as I am right now in Japanese back then.
And lastly, they said Western games tend to revolve around killing people and destroying stuff. This, I wholeheartedly disagree. I just think they are ignorant of the numerous games on Steam that don't revolve around killing and destroying stuff. They just aren't familiar to indie games too. So I made a list of games mostly indies and gave it to this one guy. I wonder though if he really will research those games or just throw that paper away.
I think it all boils down to familiarity. Battlefield series is pretty known within my class. There's this one classmate who liked Skyrim too. I wonder if Western companies try to advertise their games more aggressively with proper Japanese localization, maybe Western games would become bigger and hell even PC gaming in Japan.
What do you think?