Long Love Letter (2002)

Original title: ロング・ラブレター~漂流教室

It's January 7, just after the New Year begins. Make up classes are being held for students that aren't keeping up with their daily studies; anxious students are there to discuss their exams; and club activities are still in progress. Asami Akio, a teacher, finds himself at the gate of the school with Misaki Yuka, a woman he met long ago and had lost contact with. Before he can explain their disconnect, a group shudders as an earthquakes rocks the school. When it subsides... nothing is the same.