A genuine natural hot spring flowing directly from the inn's own source, at 100% purity with no added water and no circulation. There are two baths, the large public bath Kanichi-no-Yu and the small bath Omiya-no-Yu, where guests can soak in fresh, renowned hot spring water at any time throughout the night. This is a prestigious hot spring inherited from a villa belonging to the former imperial Kuni family, and it is highly praised for its skin-beautifying effects and excellent heat retention, even by hot spring sommeliers.

Five scenic private open-air baths lined up on the rooftop, offering a sweeping panoramic view of the beautiful Sagami Bay. If available, they require no reservation and are free of charge, allowing guests to enjoy a luxurious private bathing experience as many times as they like. Some bathtubs were newly installed in 2023, and at night guests can soak in baths lit with a moody glow while fully enjoying the distant city lights, the starry sky, and the sunrise rising from the horizon.