Water occupies 70% of the body composition. The optimum thermosystem required by the body As it may be experienced in half-body baths or hot springs, warm heat by water, with effects of balancing body temperature and making the circulation of blood smooth, is the most suitable warm heat system. The hot water circulation warm heat system of KEOYOUNG ONSUPIA furnishes sleeping conditions desired by our body. Automatic coercion method without putting a heater in water Breaking from the conventional hot heat method that water is heated by a heater inside the tub, we have developed innovatively thermal efficiency, electric safety and heat conductivity by adopting the indirect automatic coercion method only for ONSUPIA. Unchallenged technical power through patented technologies Getting out of the existing primitive heating method of a water tank, we developed a new technology, recognized as a patent, that heats partially water moving in a moment, and the technology is applied to minimize a time required for heating and to realize the maximum heating effect with the minimum water. New material adopted Bio Tension Mattress the new light material that disperses body pressure evenly, which is not hard and heavy, is adopted for providing the user with the most comfortable sleeping conditions with cozy cushion feeling.