Dormitory-based Sakuragaoka Gakuen. The school built on the waterfront is said to be strong against earthquakes, but it collapses due to the earthquake. The hero who barely survived, Shinichi Kawahara, his best friend Takaaki Tsumura, his childhood friend Fukiyuki Momose, and the only daughter of the school-funded company, Senju, and his junior, Senju Mizuba.
Each of the four will start searching to find an escape route from the collapsed school. However, the desolate situation of the collapsed school destroyed the reason of his best friend, Takaaki. What happens to them in a closed situation …