That is the most marvelous drama I've seen. Frankly speaking I started watching it only because T.O.P. was in the cast but as soon as I started the plot with it characters just took me in them. Everything was so realistic and I fell in love with ever character, trying to understand the purpose of every action done. The OST were awesome (I'm a little bit disappointed though, as Hallelujah by Big Bang was played only two or three times). And you know what? Before watching I heard that IRIS was quite boring and stupid and almost believed it. That is why remember, NEVER JUDGE ANYTHING JUST BY OTHER'S SAYING! It is better to see once than hear a hundred times about it.