That class in the school held a secret that nobody must speak of…Spring, 1998. When Kouichi Sakakibara (15) transfers to Yomiyama North Middle School, he senses something out of place in the atmosphere of a class that seems to be afraid of something. Kouichi is drawn to a mysterious girl, Mei Misaki, and tries to make contact with her, only to find more mysteries. As he does, the class is stricken by a disaster that nobody could have imagined! Just what is going on in this “world”?