It’s a late March afternoon, and the mountains of Japan are awakening to spring as Rob Tull dozes in his living room. The soft-spoken Englishman hails from a small town on Great Britain’s southern coast, and after living abroad for nearly three decades, he has finally found a place to put down permanent roots with his wife, Junko, who is originally from Okayama.

The home, with its sprawling glass surfaces and sharp angles, could feel out of place this deep in the woods, but nature doesn’t seem to mind it. A pack of wild macaques arrives to clamber over heaps of firewood, and their cries enter the house via an open kitchen window. The monkeys can see Rob and his family going about their daily life indoors, but they remain unfazed.

This house is a besso, a Japanese term for a countryside vacation home. Although Rob and Junko would like to eventually live here full-time, they are currently tied to Tokyo because of their work in finance. They escape a couple times a month with their daughter to Karuizawa, a mountainous enclave in Nagano Prefecture, about an hour northwest of the city by bullet train. “The location is just too convenient,” Rob says. “We were won over by the practicality of it.” Most Karuizawa besso are uninspired prefab cubes or stereotypes of American log cabins, but the couple knew they wanted something different.

They found their architect, Rei Mitsui, in a uniquely Japanese way. Junko met him at a formal tea ceremony, and they bonded over their love for traditional culture and aesthetics. A former associate of Shigeru Ban, Mitsui has designed projects ranging from traditional sukiya tearooms to minimalist homes.

Rob remembers seeing Mitsui’s design concept for the first time. “Wow, that’s different,” he said, semi-speechless after years of expecting to retire in a traditional kominka farmhouse. Still, it felt right. Mitsui was given free rein to let his imagination run wild, and he delivered a 1,085-square-foot cabin with two multilevel wings connected by a living space.

“The home is designed to physically and conceptually integrate with the natural environment.”
—Rei Mitsui, architect

The undisputed centerpiece is the sunken living room, which is fully covered by a sheet of glass set at a steep, 50-degree pitch. Mitsui admits that though it’s “conveniently called a roof,” the glazing serves “as a simple plane” to provide shelter from the elements. He aligned the daylit room to prevent direct midday sun exposure while maximizing moonlight.

A custom linen couch sits across from a fireplace carved into the edge of the sunken space—a far cry from the cast-iron potbelly stove that Rob expected to find in a besso. The pile of ashes in the cave-like recess competes with the glass above as the most compelling element of the room. Whether warmed in the winter by fire or cooled in the summer by breezes from the nearby sliding doors, it’s a space that both demands and disperses your attention.

Eyeing the monkeys getting closer as they scavenge for fallen chestnuts, Rob considers closing the screenless sliders. He loves the proximity to nature and enjoys taking daily walks; even the journey up to Karuizawa brings out his naturally laid-back disposition. “My life has been a succession of rentals,” the formerly rootless expat says. This besso is his chance to find a new way of living.

Roused from reflection, Rob steps up into the kitchen and dining room, where he also enjoys spending time. When the family is here, they prefer to cook rather than go out. These common spaces are exceedingly simple, so as not to distract from the structure of the home itself.

“I love the peacefulness of it—not just the house, but the trees, the walks, the nature you can find nearby, the waterfalls. The pace of life slows down.”
—Rob Tull, resident

Mitsui says that as he was designing the residence, he thought of “the most primordial spaces created by humans.” The slope of the roof and the sunken fireplace conjure up the image of a dirt lean-to from the Jomon era of Japan’s early history. Junko agrees enthusiastically. “There’s an ancient feel to the house,” she says, pointing out how the rugged personalities of the boulders in the garden bring a sense of animism to the property.

Another touch of the ancient comes in the form of two wooden support structures that hold up the wings of the house. These are modeled after torii gates, the simple pillar-and-lintel structures that mark the entrances of Shinto shrines in Japan. Shintoism—arguably not a religion but a way of life that coexists with nature—stretches back into the unrecorded past, and Mitsui explains how the gates create “a universal and symbolic composition that imparts strength and stability to the space.” They stand in magnificent contrast to the glazed areas, which appear to lack support.

Three bedrooms are located in the two wings of the house, which also have steeply sloped roofs. The ground-level primary bedroom is painted a surprisingly inviting gray lavender, Dead Salmon, by Farrow & Ball—the name makes Rob chuckle. A floor-level window next to the bed is uncurtained, providing little privacy. Rob and Junko don’t mind; it offers great opportunities for nature to present itself. Deer often come right up to the base of the pillar that sits just beyond the glass.

Their daughter’s room is in the opposite wing of the house, up a stairway and behind a low doorway with an arch that references a tea ceremony room. At the same level on the other side of the house, a tiny guest bedroom has a compact wooden deck.

“We’re still thinking about how to use the space. The house is a little too neat now, but time will solve that.”
—Junko Tull, resident

Completed in April 2024, the besso is still new to the family, and it remains unadorned. “It feels like home, but we’re still easing into it,” Rob explains. “We haven’t done enough yet to make it feel like ours.” He’s clearly in no rush to finish it, chatting at the kitchen table with Junko as the afternoon fades. “The house is a little too neat now,” Junko adds with a smile, “but time will solve that.”

This quiet moment is shattered when a monkey enters the house through the kitchen window. Junko notices first with a scream, and Rob jumps up to shoo it away. It’s a genuinely terrifying moment, and the couple exchange exasperated looks that quickly melt into laughter. By the time their daughter runs downstairs to investigate the commotion, they’ve come to accept that the besso life is bound to occasionally blur the line between the wilderness and domesticity. “That’s what we’re here for!” Rob proclaims.

Project Credits:

Architect of Record: Rei Mitsui Architects

Builder: Daiichi Construction

Structural Engineering: Ryotaro Sakata Structural Engineers

Fireplace: Keidan

Kitchen: Matsuoka

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