Somehow, all through the 20 episodes of Iris-1, Ailiseu (original title), I was able to keep the characters straight, although Westerners have difficulty sorting faces of Orientals, and the names are tricky, too. In Iris-II, I don't know who is who after a single viewing, although the performers are quite capable of portraying a character, and delivering some great stunt-fighting, also.
From IRIS-1, I think the head of the North Korean Secret Service is the same guy (but we don't see him much), but the main holdover character is double-agent, Park Cheol-yeong, who is imprisoned now by the South Korean Secret Service (NSS), of which he was once a top boss. Anyway, IRIS wants him back, since he (alone) knows where some nuclear weapons are stashed. There are a few battle scenes and ambushes that involve IRIS bad guys attacking NSS units, nominally to get Park back. Park is having second thoughts about his nefarious connections, however. The rest you will have to figure out. Some characters seem to be playing on both sides, which will probably have you saying, 'Boy.. he sure looks like that other guy who plays for the bad guys..'. He (or she) may actually be doing that - I can't say for sure just yet.
No word on our heroes from IRIS-1, which, after 20 episodes, was destined to have a happy ending and marriage for the two star-crossed lovers & protagonists of the series, when, in the final frame, a sniper's bullet ended all that. Unlike an American Soap Opera, at least we didn't get both lovers surviving with temporary amnesia! Nonetheless, I was hoping for some wrap-up or concluding info on that tragic event, but the Producers played hardball, and just carried on with a new potential crisis. O, well, woe is me.
IRIS-II is a good shoot-em-up entry, lacking the scope and intricate character development of the first series (this is only a 2-hour movie, after all). It might give you partial closure on IRIS-1, but, I think it's a bit muddled: looking at the photos on the DVD jacket, I couldn't tell you any of the character names, nor distinguish the bad guys from the good. At least there won't be an IRIS-III (if they ever do make one, I will write the producer and ask for name tags).
6/10 Canuckteach