Rei, a married gym instructor, plans to spend a rare vacation abroad with her husband. But her husband has no interest in their married life, so she travels with a friend instead. A week later, Rei returns tanned from head to toe. While her husband remains indifferent, her adult gym clients cannot take their eyes off her bronzed body. The trip has loosened Rei's inhibitions and awakened her sex drive. Hooked on the thrill of being watched, she begins using personal instruction as an excuse to boldly tease and seduce her clients...