Those who will be affected by the "Calamity" are the students of the class and their blood relatives.
After more and more people die, the students of class 3-3 hold a camp at Mount Yomiyama in an attempt to order to stop the Calamity that has begun.
Just before the camp, Kouichi and his friends find a cassette tape left by a student of class 3-3 from 15 years ago - the only year in which the Calamity suddenly stopped. They learn the method to stop the Calamity, but...
The shocking truth is revealed at last in this final volume.
