I dont know who’s who except maybe Kim Hyun Joong (did I spell his name correctly?). Not really liking the actor who played Tsukasa. Ehm, he looked kinda old there. Furthermore, that curly hairstyle -err, looked fake
The title of the drama is “Boys Before Flower”, a bit different from the English title of the Japanese drama, which was “Boys Over Flower”.
Source: SINA / re-uploaded by fangorn @ reikanorakuen.wordpress.com