I immediately wanted to watch this after knowing the cast. And I was not disappointed in the acting department of the movie. I've seen almost every actor in this movie in really different roles and I was immensely impressed by their acting here. Although, I'm not sure if people who are unfamiliar with the cast will enjoy it as much as I did.
The characters' personalities were very eccentric as most Japanese teens in dark disturbing movies are (which actually makes me wonder: are there really Japanese teens with these dramatic and over-the-top reactions and principles or is this just a reflection of anime/manga characters?). However, each character's experiences are a great representation of the different reasons for suicide. That was also one of the best parts of the story: how characters have conflicting reasons on why they want to end their life.
The ending, for me, was great but could have been better. However, the actors made it convincing enough for me to accept it.
I think the movie was overall beautifully shot although I did feel that they achieved it with struggles. In terms of the pace, it's slow as it should be (maybe a bit too slow in the beginning but it did add some tension). It also felt a little bit incomplete.
In summary:
good points - fair representation of suicidal teens, cinematography, acting
not so good points - it's hard to take the situation seriously if you're not familiar with this kind of genre of japanese film (this hardly counts as a con)
bad points - it's not the greatest film but it's on its way to be if they pushed harder (specifically on the ending)