In 1987, Pico Iyer decided to relocate to Japan. Born in the U.K. to Indian parents, in 1957, Iyer was already a successful writer, living in New York and working as a correspondent for Time, but he had long been drawn to Japanese culture, and he relished the idea of a year of quiet and solitude. He arrived in Kyoto with a plan to live as a Buddhist monk for a year, but instead he fell in love. At a ceremony at a local temple, he met Sachiko, a thirty-year-old woman with two young children, a salaryman husband who was never around, and an electric, curious mind.

Iyer’s memoir “The Lady and the Monk,” from 1991, chronicles the relationship that grew between them during that year. Sachiko had lived the circumscribed life of a young Japanese wife; she had rarely left her home city. But she was as eager to talk about classical Japanese literature as she was to get Iyer’s takes on John Denver, Robert Redford, and Carl Jung. Iyer writes that she brought a “sense of moment, as well as depth,” to their every encounter; “she made our friendship seem a sacrament.” In the course of the book, as Sachiko and Iyer explore Japan together, she decides to leave her husband and make a new life for herself. Fascinated by travel, she trains to be a tour guide. The book ends with Iyer accompanying her on her first trip out of Asia, to Sydney, where she is so moved by a visit to the beach that she takes off her shoes and runs barefoot through the city’s streets.

I read “The Lady and the Monk” last fall, during my first visit to Japan. It was a beautiful introduction to the country and its customs, with long passages on Japanese notions of women as seductresses and monks as a moral force, on the cultural obsession with the seasons, on trying to connect with locals as an interloper. But what stayed with me was the portrait of Sachiko, a woman of such irrepressible intelligence, constrained for so long and now on the cusp of a new life. It was only after reading the book that I learned, in an e-mail exchange with Iyer, that his relationship with Sachiko did not end where the memoir left off: the two have been together for thirty-one years, and live together outside of Kyoto.

Sachiko’s real name is Hiroko (he had changed her name to protect her privacy), but Iyer described her in his e-mail to me exactly the way he wrote of Sachiko, as someone “who couldn’t be more full of freshness, life, adventure and delight.” He sent me a photo from the previous summer. Hiroko looked much as I imagined her: with a beautiful, warm smile, elegantly appointed with a silk scarf and long silver earrings, and, not at all incongruously, clutching a worn Teddy bear. She works in an upscale clothing store, Iyer said, and rings a bronze bell each morning to call forth her ancestral spirits.

Iyer is known primarily for his travel writing, his erudite essays on literature, and his wise, restrained accounts of his Buddhist-inflected striving for stillness and contentment. But memoir is an equally exquisite aspect of his œuvre. As of this spring, he has a new book out that is something of a sequel to “The Lady and the Monk”: “Autumn Light: Season of Fire and Farewells,” which returns to the subject of Japan, and to the life that he has made with Hiroko there, from the vantage of late middle age.

The event at the center of the book is the sudden death of Hiroko’s father. Her mother, already suffering from dementia, begrudgingly moves into a nursing home. Perhaps more painfully, Hiroko’s estranged brother, Masahiro, refuses to reëstablish contact, even in the face of loss.

In chronicling this family tragedy, Iyer continues to grapple with his chosen home, a country known for its reserve toward foreigners. (“Autumn Light” is the first of two books that Iyer will publish this year on Japan; the second, “A Beginner’s Guide to Japan,” is due out in September.) He mentions the curious provincial habits of his neighbors, the two white kittens that a computer store placed in its shop window to attract customers, the unimpeachable centrality of the park—with its avenues of ginkgoes and maples and cherry trees—to community life. Even in his daily life, playing Ping-Pong with neighbors, he is a consummate tour guide, knowledgeable of his surroundings yet alert to all that might strike foreign eyes as unexpected or inexplicable.

The Hiroko of “Autumn Light” is in her sixties, her two children now grown. But she is in many ways still the “thirty-year old girl with daydreams” whom Iyer described in “The Lady and the Monk.” She keeps a calendar adorned with stickers of Peter Rabbit; she listens to American music on a Discman on her way to work. She honors her late father every morning, preparing his favorite tea to place at an improvised shrine, and spends the first day of autumn performing the miniature spring cleaning that is customary in Japan. A friend describes Hiroko as a “beautiful storm”: “It’s like you get picked up in this fast breeze and carried somewhere you can’t guess at. You don’t know what’s going on, but it all feels magical, a kind of dream.” In first introducing herself to that friend, Hiroko said, “I’m sorry, I little crazy lady. . . . My son say I have only accelerator. No brake!” Iyer agrees with her assessment: “And though every decision she makes is crazy, it always proves the right one.”

To my relief and pleasure, Iyer seems just as enchanted and enthralled by Hiroko as he was in “The Lady and the Monk.” “Autumn is the season of subtractions, the Japanese art of taking more and more away to charge the few things that remain,” Iyer writes. In the autumn of his life, Iyer remains alert to beauty as well as to loss, but his book is replete with a quiet assuredness, a knowledge that he and Hiroko have found the kind of love that endures. “In the luxury of our shrinking and uncluttered days, I recall why I was so glad of an empty room when I left my crowded life back in New York City,” he writes. “As Hiroko tells me stories from her girlhood before breakfast now, I give myself to her entirely, for as long as she speaks, with nothing else to carry me away. She does the same in return.”