Never in my life have I read such a brilliant manga... and believe me, I have read A LOT (but Shoujo mostly). This manga starts off a little weird. One the first few pages I was a little disturbed admittedly and wondering what the heck was going on, especially since the summary really put me off. But, thank gosh I kept on reading!
The ending of the first chapter was really something. I fell in love with it because I had never read something with a mixture of morbid as well as romantic cliché scenes which somewhat gave off a gothic feel (though it's not really a Gothic manga). There was also very few smut scenes but I feel it was well-balanced along with the plot. And the art is just amazing!
The plot is quite tense but really, you just can't put the manga down once you get into it! It's just truely amazing. I admit the romance is extremely cliché but it fits with a complicated plot like this.
But maybe they should have focused on perceptions such as Mashiro possibility of being 'homosexual'... But then again, I guess there is no genre stating Shounen Ai or Shoujo Ai and it might put Yaoi/ Yuri haters off.
The characters are very well portrayed. You hated and loved them all, which is perhaps why I love this manga. It showed how everyone had a flaw like in reality. It was also interesting how everyone in this manga seemed to use others. It could get depressing/ annoying at times but just face the facts - that's what we all do!
The main character, Mashiro pissed me off most of the time. Nevertheless, I couldn't help liking him/ her at the same time. It was as if he/ her was portraying how us human make our decision whether it is wise or not.
Kureha is just awesome. Although she was whiny near the beginning/ middle, she really tried to fight away her fears and became strong. I seriously admire her for that. And in this case, it was as if the mangaka was now portraying our 'strong/ independant' side we have.
As for Sou, we all love him! He just made this manga so amazing... His character portrays our 'weak' side of humans or how we need to 'rely on others'.
I disagree with mogiks about the minor characters just 'dissapearing'. They were pretty vital as they gave away some of the clues or attempt people to not predict what would happen.
And as for the dream-like world, I thought it was even more interesting. I mean it represented the character itself and it made me think what would I be.
I also came up with a theory, for example:
Some people have said that once the people 'graduate', they are reborn. However, I disagree with this.
In my opinion, the people attending the school are like sperms. As for the black hole, it's like a womb or the ovary. And do you remember a minor character dissapearing because she hadn't attended class two weeks in a row? This is as if her sperm died out due to lack of speed or something.
As for the nurse looking like Mashiro's mother. I was thinking that maybe the nurse looks different to everyone, e.g. Sou's version of his nurse would look like his future mother. I could be wrong on this theory as there is no proof.
Any, I also love this manga because you can come up with different theories... Also, after reading this manga my whole idea of life suddenly changed.