As far as I have read manga, this one really does hopelessness the best. I mean there's always a sliver of hope for the main characters but always only a sliver. The MCs are always just a few precious moments away from death and that constant pressure casts all of their seemingly normal actions in a peculiar light. We have school trips, the beach episode, love rivals and even studying for finals. All these normal high school manga activities all while the main cast knows that they will probably die before the year ends. It's also amazing how well the mystery element compliments this sense of dread. There's a rush of hope with every new lead only to be dashed when confronted with the cold, hard reality. Even their victories and discoveries only seem to postpone the inevitable . However, there is always that sliver of hope that keeps the manga from becoming too depressing.
Even the battles actually play out kind of like a mystery. Without giving away too many details,
there is a girl in the main cast who can see how the people around her will die in the near future. Usually, this girl has a premonition of someone's death (often by the hands of absurdly powerful enemies) and its up to the main cast to work backwards from the premonition, solve the mystery of the death/s, and combine their limited powers to overcome the powerful enemy. The actual confrontations are usually short and bloody.
The story element, as I've said, is superb. The characters are also fairly well made but, I keep hoping for some more character development. The art is... good, I guess? (I usually don't pay much attention to the art) It has plenty of gore as well, if that's your thing. The ecchiness shows up occasionally but so far I haven't noticed anything explicit. Also, each of the girls, despite each having a supernatural power, is seemingly helpless without the male lead. He buys food for them, provides shelter for them, and seems to be the only one who puts thought into chasing down the precious leads that I mentioned.
Finally, I don't understand where all of the complaints about the main character are coming from. It's true, he isn't as expressive as, say, Luffy from One Piece but that simply isn't Murakami's type of character. Murakami is the the calm, rational type of protagonist and as far as that type of protagonist goes, he is actually very expressive. He gets lost in thought, he gets angry, he cries, he gets worried when he or his friends are in danger and yells out to them in concern, he cracks jokes and, yes, he even laughed once. Honestly, with this type of tragic manga, it would be weirder if he laughed more often. He's at least more expressive than Akiyama from Liar Game or Tatsuya from Mahouka Koukou no Rettousei, and neither of those protagonists get flak for not being expressive. Murakami might not be a great protagonist hell, he might not even be a good protagonist (though I like him), but he isn't weighing this manga down with his expressions.
