Despite taking place in the Harry Potter setting, this story uses no characters or other material from the source novels and makes only sporadic use of some plot points. To be precise, it takes place at the "Salem Witches' Institute" (mentioned exactly once, in the fourth book) several years after the events of the series.

This choice of setting is intended to demonstrate that the decision to set a story in the continuity of someone else's work does not necessarily have any particular effect on the story itself. 

Disclaimer: Harry Potter, the Harry Potter universe, and any publicly recognizable elements thereof are property of their creator and licensced publishers and distributors, including but probably not limited to: J. K. Rowling, Bloomsbury Publishing, Arthur A. Levine Books, David Heyman, and Warner Bros. Entertainment, Inc. The author is in no way associated with these or any other owners, creators, producers and/or distributors of the above franchise. No copyright infringement is intended, as per the fair use provisions of any applicable jurisdictional and international laws.