River Oyunuma Natural Footbath is a free natural footbath in the Noboribetsuonsencho area of Noboribetsu, Hokkaido, where water from the Oyunuma pond flows through the Oyunuma River. It sits a 5 to 10 minute walk from Sekisuitei Ryokan and is visited after seeing Jigokudani, Okunoyu and the Oyunuma pond. Black soil is visible under the shallow water, and small styrofoam cushions are placed for users. Water temperature varies with the weather, and in winter the water can be lukewarm at a little over 30 degrees.