Bukyo is the capital of Hingashi. Kugane is just a port city, but because it's the only city open to foreigners, all the consulates and such are there. You're right that there is some class issues in Hingashi, specifically the peasantry have no means to effect change, and life is not easy for them. Even joining the Sekiseigumi, which is about the biggest thing a non-noble can do in their life, does not improve their lot dramatically. However, there's no indication this will blow up anytime soon. The SAM quests 60-70 involve you putting down a ronin traitor to the Sekiseigumi and his attempt to overthrow Hingashi. Beyond that people aren't thrilled but that's true everywhere.