At a major trading company, "Yuichi" and his subordinate "Aino" were having an affair. The two, strongly attracted to each other, gradually deepened their relationship. However, "Yuichi", who has a family, always returns home on the same day after their trysts, and they had never spent the same night together... Their first hot spring trip... The first night they spend alone together. In a secluded inn far from everyday life, where the scent of hot spring water lingers, a passionate secret rendezvous between a man and a woman entangled in an illicit love.
