is there anywhere where you can check your transformations after they happen?
Just incase you haven't found it or if anyone else wants to know, the mirror in the bathroom of the MC's house does this, not to be confused with the bedroom mirror.
There are actually a number of interactive items in the house most if not all upstairs. The wardrobe to change into unlocked costumes, the bedside table with a book on it which shows the credits, and the book on the desk to the right of the bed for discovered notes.