Jung Woogyo, who has lived a long period without sex, enrolls in a four-week confidential sexual therapy program. To his surprise, his therapist is the composed, highly professional—and strikingly fit—Park Heesu. From the awakening of hidden sensitivities to increasingly intense sessions of deep physical connection, Heesu guides Woogyo through unexplored realms of sensation. Each lesson becomes a pulse-racing journey of body and desire. But as the program nears its end, what began as a strictly professional arrangement slowly transforms into an irresistible temptation neither of them can easily walk away from.