A Tokyo Spa Built from Pink Salt and Raw MDF
By blending raw MDF with Pakistani pink salt and hand-applied plaster, Negu Inc has created a tactile sanctuary in Omotesando that physically embodies Remedy Cave’s philosophy of healing from within
When a client unexpectedly contacted Tokyo-based design studio Negu Inc with a request to build a skincare and massage space in a mere two months, lead designer Kenta Nagai knew the timeline was a challenge. But, with calm determination, Nagai and his team managed to bring Remedy Cave to life only a little later, in just three months, with a result that belies its timeline. Tucked away on a quiet back street off the Tokyo’s bustling Omotesando, the space was thoughtfully designed to physically embody the brand's core philosophy of ‘healing from within’. The resulting environment offers visitors a sanctuary, enveloping them with a sense of security and tranquillity much like a physical cave.
To achieve this distinctly calm atmosphere, Nagai deliberately avoided visual noise by relying on just three primary materials: Pakistani pink salt, MDF and sand plaster, which was applied by hand to give the space a unique, tactile warmth. By incorporating sweeping curves into the architecture and furniture, the team sought to express the soft lines of the human body and create an enveloping atmosphere. Structural intervention was kept minimal, with a single wall built to divide the salt treatment room from the rest area.
The team's use of MDF is perhaps the project's most humble, yet crucial, detail. Typically relegated to a hidden base material, the material is here left entirely exposed without any applied ‘make-up’. Nagai's team carefully polished the edges and added a clear finish, creating a smooth, nuanced surface that Nagai notes somehow resembles traditional Chinese ceramics. This raw, authentic approach was a deliberate reflection of the store’s purpose. ‘Skincare doesn’t cover the skin,’ Nagai explains. ‘Skincare is used to make the skin better. So, we used the same process — rather than covering the MDF, we made it better.’ By quietly and carefully elevating a basic material, the team gave physical shape to the idea of inner beauty.
The store’s centrepiece is a specialised treatment room built entirely of thick pink salt bricks sourced directly from Pakistan. Working with this unconventional material posed a unique logistical hurdle for the team. Because pink salt bricks are virtually unused in Japanese construction, Nagai struggled to find a local vendor who knew how to install them. Eventually, he tracked down a specialised sauna contractor who understood the specific glue and techniques required to secure the heavy blocks.
Throughout the space, Nagai shifted his focus to a holistic, experiential design rather than rely on grand architectural gestures. The studio designed the brand's product packaging and incorporated physical ingredients from traditional Chinese medicine into the visual landscape to harmonise with the brand’s signature worldview. And to complete the sanctuary’s atmosphere, they draped simple cloth over basic fixtures to create custom lighting, allowing a soft, gentle glow to diffuse into the space.
Text by Katherine Ring
Images by Junpei Kato
