With the rapid increase of young suicides, the government initiated a research project called CYP (Civilize Youngsters Project) to analyze their psychology. They pick up children from all over the country at random, and put them into a facility under surveillance. A device is surgically put into each of them. They are told if they push the button, their heart will stop. With the stress, most push the button within two years.
Minami is a young man working in this facility as a guard. He feels he is losing emotions by seeing so many deaths here. But he finds something curious: there are 4 boys and girls who survive here for 7 years. He wonders why they don't push the button... (from DramaWiki)