Finding our way back home (bsd x reader x Harry Potter and the chamber of secret
18 parts Complete Book 3
It's Dazai, Ranpo, and (Y/n)'s 2nd year of Schooling in Hogwarts and they still haven't found any clues to bring them back to their universe except for the emblem that Dumbledore give to them.
They just hope that their theory are true, that they have to complete a task to come back to their universe, and they hoped that the mission that Dumbledore give to them will be getting interesting unlike their 1st year schooling.
(I don't any of the characters)