A new private rental villa, “BeachFot MON,” has opened in Katsuura City, Chiba Prefecture, with the ocean directly in front of the property. The facility is a modern Western-style 1LDK private villa designed around the concept of “the sea and the moon.” It features a refined space where guests can feel the presence of the moon from both inside and outside, along with sweeping views of the Katsuura sea, a custom-made Japanese barrel sauna, and a BBQ terrace. The villa is designed as a whole-house rental where the stay itself becomes the main experience. Its greatest feature is the location: guests can leave the sauna room and immediately move through rinsing, outdoor air bathing, and even diving into the sea. The full sequence of “sauna, cold bath, outdoor air bath, and the ocean” can be enjoyed seamlessly within the property. Located along Katsuura’s beautiful coastline, BeachFot MON is built around the idea that “the moon can be seen from both inside and outside.” The interior, lighting, and exterior design are unified under this concept. During the day, guests can look out over the Katsuura sea and sky; at night, they can spend time surrounded by moonlight and the sound of waves. The first floor features a full-scale barrel sauna facing the sea and a carefully designed relaxation flow. The custom-made Japanese barrel sauna matches the villa’s exterior color scheme and has a large tempered-glass window at the front, creating a line of sight where the ocean appears directly ahead upon entry. Guests can enjoy self-löyly while taking in the ever-changing views of Katsuura’s sea and sky. The sauna uses a high-powered stove capable of reaching 110°C. To maintain authentic heat even in winter sea winds, the facility balances insulation and ventilation efficiency, with air intake below the stove and exhaust at the upper diagonal side, creating ideal natural convection. The sauna space connects directly to the indoor bathroom, allowing a seamless flow from sauna to rinsing