Japan, 1944. Trained for intelligence work, Hiroo Onoda, 22 years old, discovers a philosophy contrary to the official line: no suicide; stay alive whatever happens; the mission is more important than anything else. Sent to Lubang, a small island in the Philippines where the Americans are about to land, this role will be to wage a guerrilla war until the return of the Japanese troops. The Empire will surrender soon after; Onoda, 10,000 days later.

On a normal day, a stranger breaks into Sumire's apartment and assaults her. Sumire reacts incredibly calmly to the incident, but she still feels the dangers and uncertainties creeping upon her. All that seem to be peaceful and ordinary start to collapse. As everything slips toward the unexpected, Sumire starts writing again, and reinvestigating the relationships around her.