The defining feature is the overwhelming volume of steam produced by a sauna stove manufactured for löyly by Teknoraizukomu combined with lava stones from Mount Fuji that are rich in iron and minerals. The auto löyly at :15 and :45 each hour injects a large amount of water, about 500 ml, all at once, causing high-temperature steam to explode throughout the sauna room. The top bench becomes instantly blistering hot. A three-tier bench layout and a silence-focused design with a no-talking bathing policy create a striking contrast with the roar of steam. The high heat efficiency from stacking a large mass of sauna stones generates far more steam than typical saunas.

A sauna room specifically designed for the aufguss experience. With a high ceiling and three-tier benches that fit 5–6 people per row, it secures a spacious atmosphere that balances openness and unity. Two HARVIA tower stoves perform automatic löyly every 20 minutes, and aufguss masters lead aufguss sessions every hour. The performances combine programming, music, and aromatics into highly entertaining presentations that change each time, so every visit brings a new experience.

Its greatest characteristic is the ability to fully submerge, using amber-colored well water pumped from beneath Kawasaki Ward and flowed continuously. The tub has a two-step structure separated by a handrail, with 120 cm and 150 cm depths, so users can acclimate in the shallower side before moving to the deepest section (150 cm) for full submersion. The water temperature is low, and a strong current constantly cools the skin, making the perceived temperature feel even sharper. True to its name as a submersion cold plunge bath, head submersion is officially permitted, making it a rare example in Japan. The sense of release when fully immersing the whole body after a good sweat is unparalleled. The well water also contains trace hot spring minerals, giving it a slightly viscous, soft texture on the skin.