OP

Quoted from Gornkleschnitzer:

A brief summary of the backstory:
- A high school is built around a dormant volcano. It's dormant. Nobody believes it will ever erupt, and nobody wants to, because it's a symbol of the school darn it.
- Among the ordinary student body are three girls - the founders and only members of the Pseudoscience Club - with inherent magical abilities to control forces of nature - water, earth, and electricity (and, after an accident with a clock, time itself). Introductions later.
- The volcano erupts, much to almost everyone's surprise, raining down wholesale death and destruction.
- Time-girl pulls a "Groundhog Day" and resets time. The trio tries to warn everyone, and fails; it's dormant, why would it erupt?
- So each of them has a plan to try to save the school from the volcano using various strategies, supplies, and magical abilities. You, as the player, are helping them make it happen.