On his Coronation day to become the head of his household, a boy named Oz has commited the greatest sin and was sent to the Abyss. After making a contract with a chain he was sent back to his world later finding out many years have passed since he had disappeared, Now that Oz is back he is trying to find out what is the greatsin he has commited.
I was fond of the way this story alludes to Alice in Wonderland, but like every story that makes such a connection, it becomes a little twisted and creepy. The beginning of Pandora Hearts really captures you and will have you wanting to read.
I would say this is more for mature readers, but if I had to give a preference on which age groups or grades, I would say probably kids of the years fifteen and up (so high schoolers and above).