I've heard that the first season isn't as great, but after that it really picks up.
Depends on what you mean by "not as great". It can be really confusing, but the action itself is just as good if not better.
From what I've heard, the first season just doesn't build up the suspense the way later seasons do. Something about not having the right mood, not enough tension, etc.
However, I haven't seen it myself, so I don't really know what to expect going in.
It's pretty much the exact opposite. Approximately every four or so episodes you get a new "arc." The first season is made up of "question" arcs primarily - you get a whole lot of crazy things going on, and then the arc starts a new, either with a different character added in, or a different decision made. However, you don't get a resolution until near the end. Up until the end you're wondering just what the hell is going on, and even at the end of the first season you're not sure.
The entire mystery is revealed within the first couple of episodes of season 2. Gone is the violence, which isn't such a bad thing (episode, what, 17 of the first season? UGH. Made me queasy), but gone too is any of the questions. Instead it's like "Oh, here's what happening." The ending arc is nice, but drawn out - you know who the bad guy(s) is(are), you just need to see how it'll work out. The very ending changes the feel from demented psycho ward to Home Alone - foil the bad guys with booby traps and pranks!
... what? I don't want that! We've seen what these kids can do with baseball bats, hatchets, and knives - let them go to freaking town!
So while the first season is just one series of mindf*cks after another that leave you wondering what's going on, the second season lays all the cards out right away and then fine-tunes the points until you reach the "happy" ending.
The end of season 1 is still the best ending, even if it turns out to be a "won the battle, lost the war" kind of thing.
One final fun piece - I dressed as Tomitake for Halloween last year. Was a lot of fun, although people just thought I was a random guy with his throat cut open.
Retired News Writer for the ZAM Network
WoW - Aureliano the Insane - level 90 Druid on Sen'Jin
Nanaoki - level 90 Mage on Sen'Jin