Groundhog's Day
It's a blurry line, dream and wake. So when Buffy and her friends wake up and are back in high school they assume it's a dream. If not a nightmare. The problem is, they remember this day, remember everything about it. It's honestly a little spooky how very much detail they remember. Like when someone goes to spill a drink and they catch it before it hits the ground. When the fire drill no one is expecting goes off and they are already packed and ready to go.
This isn't a dream, and it's not just a normal day in Sunnydale High. Then again, what's a normal day on a Hellmouth? They are stuck in time, stuck in high school! It's not just them either, little by little they run into old friends, ones that weren't even in high school with them, but are now trapped under the tutelage of Principal Skinner.
So why? What are they supposed to do? And how do they fix it? Because no one wants to be a junior in high school forever.
Canon and originals welcome. Canon from later seasons also welcome but will be students or faculty at the school. Feel free to ask questions. Auditions have begun.