This memorable tale of how easily the ordinary can veer into the extraordinary or even abnormal is portrayed through the experiences of the unsettled female protagonist, Asahi Matsuura, 30. Her husband, Muneaki, is transferred by his employer to a workplace near his parents' home. The rental unit his parents own next door happens to be vacant, and as they've offered the place to the young couple for free, Asahi decides not to worry about finding new temp work right away. They move in on a day of heavy rain near the end of the rainy season. Muneaki's grandfather also lives next door with his parents, who both still work outside the home. Apart from a supermarket and a convenience store, there is virtually nothing of interest in the vicinity, and Asahi finds herself with little to do.
One day Asahi's mother-in-law calls to ask her to get something at the convenience store. On the way, she comes upon a black creature of some kind that's "neither a dog nor a cat nor a weasel nor a tanuki nor a boar," and she pursues it as it flees toward the river. Suddenly, her feet drop out from under her, and she finds herself stuck up to her chest in a hole, unable to free herself?until a woman who lives nearby finds her and pulls her out. When she reaches the convenience store, she meets a middle-aged man, and to her considerable surprise, learns that he is Muneaki's reclusive older brother, who has been living by himself in a shed for the last 20 years. Neither Muneaki nor his parents have ever mentioned to her that he has a brother.
Muneaki spends his time constantly texting or blogging on his mobile phone, even during meals, and barely speaks to his wife. His grandfather appears to suffer from dementia, and is apt to be found watering the plants in the yard even when it's raining. His mother's perpetual good cheer is certainly welcome, but unfortunately she never stops talking. His brother is very popular with the neighborhood kids, who for some reason all address him as Sensei ("teacher" or "professor").
Besides the title work, the volume contains two additional short stories about a newlywed couple who live in an old farmhouse visited by weasels.