In Japan, a country that worships hot water, many people begin their day with a sip of green tea and end it with a soak in a deep tub. Designed by Curiosity, a Tokyo-based multidisciplinary design studio, this residence at Uehara Gardens, with its chef-ready kitchen and spa-like bath, caters to both appetites.

Located on the top floor of a “mansion” (as Western-style luxury apartment buildings are known in Japan), this recent renovation for a family of four features a sublimely spare interior intended for relaxation. “All your senses should calm down inside the home,” explains Curiosity president Gwenael Nicolas. Defined by muted gray walls, softly lit ceilings, and custom furniture created for comfort, the heart of the home is its expansive living/dining room. Tucked in back are three bedrooms, also surfaced in light colors. Against this backdrop, the kitchen and bathroom—both encased in distinctive Mongolian granite—seem like a matched pair.