Tokachigawa Onsen, located in Otofuke Town, Kato District, Hokkaido, is renowned as a rare 'Moor Hot Spring' on a global scale. The earliest record of this hot spring dates back to 1874, and among the Ainu people, it was known as the 'Medicinal Swamp.' In 1900, use by Japanese settlers began, and in 1933, it was officially named Tokachigawa Onsen. In 2004, it was designated as a Hokkaido Heritage site for its Moor Hot Spring. Moor hot springs are formed when groundwater passes through peat layers (lignite deposits) created from ancient plants like reeds that accumulated over millions of years, resulting in water rich in plant-derived organic substances such as humic and fulvic acids. The water quality is sodium chloride-bicarbonate spring (weakly alkaline, low-tension, high-temperature spring), gushing at 55-60 degrees Celsius from 500-700 meters underground. Known for its skin-smoothing and regenerative properties, it is beloved as a 'Beauty Hot Spring' for its moisturizing effects similar to cosmetic lotion. Located along the Tokachi River flowing through the vast Tokachi Plain, this spa town offers healing surrounded by abundant nature.