In a small town in the mountains on an isolated island stands the Ultramarine school. At school, this is forcibly studied by children who scored a high score in the state test for social incompatibility. The protagonist Kurosu Tati, who received a deep emotional trauma in his childhood, is gaining an incredibly high score in this test and is getting into this school. His life becomes more joyful when, against his will, he gets into the radio broadcasting club and brings other students to him. The club has 8 members, and everyone has their own cockroaches in their heads. But the fun life of the radio club does not last long. After a series of tragic events, the members of the radio club are seriously quarreling among themselves. In a desperate attempt to reconcile them, Taiti organizes a training camp at a mountain camp in the last days of the summer holidays. But this only turns into bigger quarrels. Frustrated and irritated, the members of the radio club return to the city, but waking up, discover that in addition to them in the city there is not a single living being. Bacteria - and they disappeared (the food stopped spoiling). No electricity, running water does not work. Only mysterious Nanak girl sometimes meets on the way of the main character, each time disappearing without a trace.