A psychological horror type manga directed more towards kids than adults (as I'm sure you can pick up from the dialogue in the first chapter)

Story-
Middle school graduation day, boy goes to tell girl his true feelings, ends up waking up locked in his school with 11 other classmates, and the plot begins from there. I've watched/red plenty of students trapped in the school types, but this ones got just enough creativity to the plot to make it unique.
Art+Character-
The arts lovely, all the students are well drawn and have their own distinct design, instead of being the generic character types were all so used to (except the super religious girl, she's here, and as annoying as always)Through the 35 chapters I've read the characters also go through a lot of progression, changing the longer they go through the horrors in the school.Is it worth it to protect your friends?Who caused this to happen?Will violence solve my problems, or should I run and hide?
Enjoyment-
Although made for children, and being a bit bland with the horror scenes and dialogue, I read all available chapters in one sitting.(though they're kinda short)Each chapters leaves you with a cliff hanger wanting more each time.


Overall, it's a good manga to read in your leisure time if you're looking for something more fast paced and not too serious, but serious enough to keep you interested.