Yeolhwaokmun.

Dong-goo and Yeon-hee are losing their love and affection for each other because of their insensitivity to sex and sexual preference due to being married for a long time. Then one day, Dong-goo hears the story of sex master Wang-nan from his sex partner Yoo-gyeong and finds her for a different sex. After many twists and turns, the two, who found Wang-nan's disciple Min-yong, began training to receive the essence of sex from Wang-nan. However, Dong-goo began to rebel with doubts about the training of Wang-nan. However, Yeon-hee is so into Wang-nan. Will Dong-goo be able to protect Yeon-hee from them?