If you see an item out of the ordinary within one of the rooms, that’s where you’ll find the mini game.

If I recall a couple of the locations correctly:

* One of them is in Milkamean’s Room either on or near the drawer

* One of them is in the cafeteria under one of the tables

* One of them is in Suki’s classroom by one of the desks

* One of them is on or near Cruxia’s throne

and 

*One of them is in between some of the Funko Pop like figurines in one of the gift shops