This sounds like a great idea. I teach in an all girls HS and they are crazy about Shinee, Big Bang and the like. I've even had almost arguments about it my classes, and Big Bang/Shinee only had a passing mention in those classes. Also I'd love for some of my students to be able to have a discussion/debate in class.
I might change about the lesson to add in some Western Music elements in there because the more able G2 students produce a good variety of western singers/bands when I asked them about their favourite - Lady Gaga, Westlife(vomit), Stevie Wonder, Beyonce, Kula Shaka(I don't know why).
I like the idea of mixing up the Western and Kpop example but I don't think that my poor stomach could stand Westlife or Taylor Swift.