Twisted Wonderland (the manga): Book of Octavinelle 1.

Stranded in the world of Twisted Wonderland, Yu must brave a magical school filled with ghosts, monsters, and uncooperative students!

Whisked away to the world of Twisted Wonderland and enrolled in the magical school known as Night Raven College, Yu encounters a strange scenario—his fellow students are doing too well on their exams! But there couldn’t be anything sinister behind great test scores, could there?