China's earliest works in the room are the first (Sutra of the Plain Woman) and (Sutra of the Mysterious Woman). These two books are called the "originator" of the works of sexual intercourse and regarded as the classics of sexual intercourse theory, so later generations directly call sexual intercourse "the study of metaphysics". Legend has it that Motome is a descendant of the Yellow Emperor, proficient in health preservation and sexual intercourse, but in fact he is just a synonym for ancient women who know about sex. Xuan Nv, also known as "Nine Days Xuan Nv", was an ancient woman who was familiar with the art of sexual intercourse, but her reputation was not as good as that of Motome. (Sutra of Plain Woman) and Sutra of Mysterious Woman are two books that were independent at first, and then merged into one. The lost version of Ye Dehui is a combination of two books. There are different opinions about the completion time of Su Nv Jing and Xuan Nv Jing.

Some said it was written in the Warring States, some said it was written in the Western Han Dynasty, and some said it was written in the Eastern Han, Wei and Jin Dynasties. In my opinion, these two books may not have been written by one person at a time. Like the classic of traditional Chinese medicine (Huangdi Neijing), the earliest part of the book may have been drafted by people in the Warring States period, and it was supplemented and processed in the Western Han Dynasty, the Eastern Han Dynasty and even the Wei and Jin Dynasties before it was finally written. Therefore, there was no finalized version in the Western Han Dynasty, so when recording various works indoors, these two books were not recorded. Focusing on "the way of intercourse between Yin and Yang", the Sutra for Plain Women and the Sutra for Mysterious Women have published many incisive opinions on men's and women's sexual life, which are worthy of people's attention.