"You didn't open it," she whispered. "You just made sure I couldn't close it again."
If you were looking for a specific or light novel version (which often serve as the "paper" source for such animations), it was originally based on works by the creator Amam (雨あられ). Toshoshitsu no Kanojo: Seiso na Kimi ga Ochiru made - IMDb Toshoshitsu No Kanojo Seiso Na Kimi Ga Ochiru M...