The story itself is separate from the main plot of Three Houses, but upon finishing it the characters and new areas become unlocked in the main section of the game as well. Because of this setup, the new story is accessed from the game's main menu, and it uses it's own save file. As long time players have already guessed, the story does take place during the first half of Three Houses, and it must be completed before you reach Part 2 if you'd like to bring the characters and new content into your main save. This is due to some pretty obvious reasons, but that's about all I can say about it. On top of this old characters hare received new supports for the newly added cast, so you have plenty more conversations and character development to witness on top of the already massive amounts of scenes the base game had.
Now with that being said, what are you waiting for? Go check it out for yourself!
