There's a ton of dedicated websites w/ mind-numbingly thorough reviews of this movie out on the net so i'm definitely going to keep this brief - but damn is this a cool movie or what? Director Kinji Fukasaku does an outstanding job w/ this flik, and i was hype to see Go Go (from Kill Bill Vol. 1 fame) playing a part. Go Go was such a cool character in such a cool scene in Kill Bill IMO.
The rest of the cast i'd never seen or heard of (even though the sensei/teacher looked real familiar to me for some reason - help me out with this if you can via a comment...).
In a lot of ways this movie reminds me of a much cooler, underground version of Running Man (w/ terminator Arnold S). Essentially you have a story about misfit 9th graders in japan being transported to a deserted island for a classic (but rarely tiresome) game of "last boy/girl alive wins" with some Lord of the Flies spice sprinkled in for good measure. There's some wild new federal law passed that serves to explain the existence of the game, and a very, very japanese training video that got more than a chuckle out of my wife.
The script does a great job of covering the gamut of possible reactions/actions if kids were thrown into a situation like this: some totally lose it (emotional responses from sadness to fear to anger to just plain psychosis), some commit suicide rather than willingly murder their classmates (or get murdered BY them), some hope, some hide, some resist. Cliques (read: gangs) form, and we learn a lot about the students previous relationships with each other via well placed, well timed flashbacks. There's even a couple of "transfer" students who signed-up (how's that for brass ones?) for this madness - one taking the role of main villain/psychotic doing-this-for-fun nut job, and the other selfless friend (with a cool past and interesting motives for sure) to our main character Nahanara (?) as he tries to survive and keep his promise to protect a shy classmate.
There is a great twist (one i won't give away here), and in the end it's a cool story loosely about trust, friendship, chivalry, and survival (not to mention a swell look at teenage relationships). HIGHLY RECOMMENDED. I'm pretty sure this is a "rent-on-netflix-then-buy-on-amazon" movie for me :)