KAI Yufuin: a modern 'ryokan' in the hot springs of Japan by Kengo Kuma

Owing to its location in the Pacific Ring of Fire, the Japanese archipelago has many active volcanoes; of the 67 volcanoes, 55 are still said to be active. However, the presence of active volcanoes in the region also contributes to a rise in the number of hot springs. Widely known as Onsen—a hot spring or a resort developed around a hot spring—the mineral-rich waters gave birth to the spa culture associated with the 'land of the rising sun'. Spas, thus formed, derived their shape inspired by the ryokan, a traditional Japanese inn. Merging the cultural familiarity of onsen and ryokan in the town of Yufuin, Kengo Kuma & Associates designed KAI Yufuin in Ōita Prefecture, Japan.

With terraced rice paddy fields as the protagonist of the design, KAI Yufuin settles in the farming village as an extension of the local character of the countryside. The contours of the 35,562 sq.m site directs the placement of different built structures, throughout the site. Assisting the site planning further is a sawtooth forest to the north, a valley to the south and Mt Yufu to the east. These natural factors thereby determine the circulation, orientation of the buildings, and the landscape design. The Japanese architects mention that KAI Yufuin provides “an experience of the rural village of Satoyama, which is the prototype of Yufuin.”

Satoyama is a Japanese term which defines the area between the mountain foothills. Historically, a Satoyama takes years to form and the factors contributing to its formation vary from small-scale agriculture to forestry use. Due to its unique geographical presence, the rural villages that take shape in these areas also behold the organic character of navigating nature. At KAI Yufuin, visitors get to experience the peculiar nature of these rural Japanese villages by the mountains.

From the east of the site, a curved road with shrub lined on its sides leads to the main building of KAI Yufuin. The linear building with a sloped roof and bamboo-clad front wall mark the visitors’ introduction to the resort architecture. At a glance, the front elevation of the hospitality architecture imparts a minimal sense of an inn, with a low-rise structure. Responding to the dark colour palette of the exterior, the interior spaces also adorn shades of black and grey. The different spaces of the building are spatially planned inspired by the traditional farmhouse architecture. The lobby space has earth furnace-style counters and tataki—traditional Japanese earthen floors—therefore it is nicknamed tataki lobby. The furniture in the space also follows the earth furnace forms and material palette of the interior design.

With the itama (wooden flooring) space, the aesthetics of the interiors transition from the tataki lobby to the zashiki. The zashiki is a long engawa space—an edging strip of non-tatami-matted flooring that runs on the outside of the building in Japanese architecture—overlooking the terraced rice fields. Along with the tatami flooring, this space is furnished with round seats and floor chairs made of Shichitoui plants of the Kunisaki Peninsula. From the zashiki, the visitors are blessed with a visual panorama of the resort with the mountains and forest of Yufu in the background. Through the spaces, the lighting design is exclusively crafted from local materials to go beyond its functionality and retain its sculptural identity, elevating the artistic quotient of the interior design.

Terraced rice fields descending the valley draw attention to the hospitality design of the site. Two cottages, designed, inspired by the ryokan, sit on the terraced landscape. Other accommodation units comprising rooms and cottages rest on the northern side of the site, in an outward-looking cluster. The interior design of the rooms follows the traditional architecture character of the ryokan, with tatami flooring, customised cane furniture, and a scale of fenestrations complementing this influence.

The use of local materials in the design elevates the farm-like elements into an art experience. Adding to the use of such a material palette, the architects share, "This was an attempt to restart Mingei culture in the post-Covid era.” Mingei can be translated as a style of folk art or folk craft that emerged in the mid-1920s, mainly considered a reaction to Japan's rapid modernisation. In the cottages by the side of the terraced rice fields, the proportions of the planning layout and its openings, and the raised platform helps visitors absorb the essence of living in a Japanese countryside.

The post-COVID era witnessed a sudden rise in rural tourism, and the hospitality sector embraced this shift, thereby building on it. Most countries, across the world, are witnessing an interest surge in tourist destinations in their countryside, resulting in the birth of a different architectural style. One that borrows from the traditionality of local buildings and settlements and presents them on the principles of contemporary architecture to deliver upon the rural experience with modern comforts.

Contrasting the architectural movement that merges the traditional and modern, here, the architecture seems to prioritise the local and vernacular character over the modern. The result of this responsible architectural response was architecture that is a symbol and embodiment of the culture of the place it rests in. This pattern of hospitality architecture that encourages the built volumes to form a relation to the land was seen in Dolkhar Ladakh too. At KAI Yufuin, architects at Kengo Kuma’s architecture studio exhibit a culturally sensitive version of a similar approach in the geographical and historical context of Japan.

The architecture of Hoshino Resorts' KAI Yufuin doesn’t appear to be a new development on the site, it sits on the contours as a familiar physical entity that ebbs and flows between the irregularity of the site. In the architects’ attempt to present the architecture as an extension of the traditional farmhouse architecture, KAI Yufuin extends to become a small rural village in the foothills of Yufu’s mountains. With the coming together of a landscape design that doesn’t seem forced in the land, an architecture that is part contemporary and part traditional, and an interior design that delivers on the characters of a ryokan, the hospitality space becomes an artistic experience of a culture, history and time that is past, but still thrives.

Project Details

Name: KAI Yufuin
Location: Oita Prefecture, Japan
Main use: Ryokan
Site area: 35,562.24 sq.m
Building area: 2,721.80 sq.m
Total floor area: 4,365.70 sq.m
Design period: February 2016 to September 2020
Construction period: October 2020 to May 2022
Building Owner: TLS6 Special Purpose Company
Architects: Kengo Kuma & Associates
Design Team: Kengo Kuma, Kenji Miyahara, Nahoko Yoshii, Hajime Nakamura (former member), Jung Won Kim
Lighting: Lighting Planners Associates
Lighting Team: Mari Kubota, Yumi Honda, Masafumi Yamamoto
Landscape: SEA BASS; Person in charge: Chiho Suzuki
Development: Kume Sekkei
Development Team: Tamaki Onoda, Koichi Sato, Shigenori Takahashi, Rikuo Yagi
Construction: Fujita Corporation; Person in charge: Hideki Okamoto and Architect: Koichiro Samejima, and Shinsei Construction; Person in charge: Atsushi Wakasa
Structure: Shu Aiura
Facilities: Hals Architectural Environmental Design; Person in charge: Ritsu Oshiro
Electrical Equipments: Emiko Kayo