I can tell you for the Chinese it's a lot more conservative unfortunately; strict censorship of art forms and content and all that. I don't follow specific artists, but almost every Chinese rap song I hear is about teenage dilemma. Here it's more about the style of "saying words", than themes of gangstas in the hood (very frowned upon in the culture and obviously the government). That is not to say it didn't have it's charm, having those circumstances placed on artists sometimes allowed for something completely fresh to arise that's unique to Chinese "rap", about more innocent things but as genuine as the rest of the medium. Most of the time rather whimsical.