Black Face?

I have a very interesting question. There is currently a production of the musical "Hairspray" that is going on in Seoul right now. It's in Korean. I have two questions about this. First, the show is about a large girl. There really are no large girls in Korea, and if they find one, can she sing? So, who is playing the role of Tracy? The other question is this. The show is about race equality. Where do they find black people in Korea? And even if they find them, can they speak/sing in Korean? So that makes me wonder, does the show have Koreans in black face. I wonder so much about this right now. How do you perform a show about racial equality when there is only one race here?