Number theory — what Gauss called “the queen of mathematics”, devoted to the study of numbers and their arcane interrelationships — does not perhaps sound like the most fruitful basis for a poignant domestic drama. And yet this novel, with its skilful admixture of tender atmospherics and stealthy education, has sold more than four million copies in its native Japan. Its unnamed characters suggest archetype or myth; its rapturous concentration on the details of weather and cooking provide a satisfyingly textured foundation.
The book is narrated by the housekeeper of the title, a single mother employed by an agency, who is assigned a new client. He lives in a dingy two-room apartment, and his suit jacket is covered with reminder notes he scribbles to himself. This is the Professor, a brilliant mathematician who suffered brain damage in a car accident in 1975, and since then cannot remember anything for more than an hour and 20 minutes at a time. “It’s as if he has a single, eighty-minute videotape inside his head,” the narrator explains, “and when he records anything new, he has to record over the existing memories.”
What he can remember is mathematics. He asks for her shoe size and telephone number, and reflects on the mathematical properties of each. Once he has drawn a picture of her and clipped it to his suit so that he is not altogether surprised to see her every day, he begins to induct her into number theory.