This is the best drama special ever, most importantly because it shouldn't even have been labelled as a special episode. This is simply the continuation of episode 20 and a better ending to every character. Even if you don't watch it, the 20-episodes show is nicely ended, so it's not like you will be left handing if you don't watch this special, but it's definitely a much more detailed and precise ending to this amazing show. It's certainly worth watching and enjoyable, so don't hesitate anymore and just go watch it.