Miku takes on the task of writing a school festival play from a manuscript she is given — and grows uneasy about its ending. She falls into a hidden fountain on school grounds and surfaces in a parallel world where her friends exist but are completely different people. In that world, the events of the manuscript keep playing out and always end in tragedy. Each time Miku returns to the real world, time has reset and the original book is back in her hands. She must rewrite the story before its ending claims the person she loves.