"The Story Treats and event stories are all AU. This means they don’t have any influence on the main story and are meant to be enjoyed separately." ¹
"Story events are special stories that occur in a universe parallel to the main story. These stories are only available for a limited time, and you don't need love passes to read them. To play story events, first you have to read the prologue, choose your first character and read on. During events, you can play as many character routes as you want. The more characters you play, the more prizes you get." ²
Story Treats were a special gacha where you could get fashion items and a story in different parts. This feature didn't exist on the original so all the stories released on GGParty as Story Treats were originally released as regular event stories on Celebrity Temptation.
So both are basically the same kind of stories, but because the way they were released on GGParty is different, I decided to put them in different sections too.