In the winter of 1980, twelve-year-old Saburo Morita tries to live a normal life, but the bizarre keeps finding him. A nearly naked man with a samurai haircut appears in his town, and his eccentric scientist father has finished building a time machine that looks like a giant metal smoking pipe. Before a proper test, a spaceship crashes outside their home. The dying pilot, a Japanese man, gives Saburo’s father a book and warns of a war between humans and an alien race that he traveled through time to try to stop. He dies, and Saburo’s father decodes coordinates to Tokyo Bay, July 2050.

Saburo, his father, and his classmate Kyoko Aoki board the pipe machine, but the strange half-naked foreigner latches onto it, demanding the book—which he calls the Bible—and damaging the machine. In the chaos, Saburo is thrown off alone and arrives two months early, in April 2050. He wakes in a strange underground complex, greeted by a girl named Kanata who looks exactly like Kyoko but is not her. When he ventures to the surface, he finds an ashy, black sky and robots demanding identification. Tokyo Bay is barely visible, and there is no sign of life.

Saburo is taken in by the underground residents, who initially accuse him of being from the wealthy Yamanote district. Kanata leads him to the Professor, who explains that the ozone layer collapsed decades ago, letting in deadly UV rays. Mankind built facilities that produce a special smoke to block the sun, but the air is now ashy, cold, and unbreathable, forcing most survivors underground. The Professor believes Saburo truly came from the past and accepts him into the community. The volume ends with a shot of the crash-landed pipe machine, leaving Saburo stranded in this dystopian future, separated from his family and surrounded by mysteries—the true nature of the alien war, the purpose of the four artifacts, and the identity of the pursuing foreigner. The story blends slapstick absurdity with a slow-burn sci-fi narrative, exploring environmental collapse, class divides, and a boy’s struggle to survive and reunite with those he loves.