Men-shen comprises two deities who guard the door of a home against evil spirits and hostile influences. Men-shen, literally means "Gods of the Doorway". They are often depicted with one god having a red face and the other a white face, both with terrifying facial expressions. Sometimes the deities are portrayed armed with special rapiers or halberds to help fight against the evil spirits.

There are also several stories about Men-shen. One version says that the Tang emperor Taizong was beset by demons outside of his bedroom at night. Two of his soldiers, Qin Shu-bao and Yu Chi Jing-de, requested permission to guard the door to the emperor's chamber and in doing so, they were able to protect him.

So, although the belief of door guardians is much older, the identification of the guardians with Qin Shu-bao and Yu Chi Jing-de is more recent, perhaps 600-700 years old. Therefore, these two have now come to be associated with the ancient threshold guardians.