DIMENSION HIGH SCHOOL

One day while going to high school recuperative classes, Junpei notices a weird rock which he then decides to carry with him; but during classes the rock started talking! "You guys are the heroes of the prophecy! I want you to get rid of the devils of destruction." Suddenly a bright light shined from the rock and when they woke up they weren't at school anymore, they were transported to a world of animation! Afterwards they get challenged by a Sphinx that appeared out of nowhere, if they can't solve the Sphinx puzzles they will not be able to come back to the real world. Can these 5 return to the 3 dimensional world? — Description from AniList community (anilist.co).