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.