Why do monsters wear masks in Natsume's Friends?

Not only the monsters in Friends of Natsume like to wear masks, but also the monsters in other comics, such as Spirited Away in Firefly Forest and so on. In fact, these are inseparable from Japanese local culture, and some festivals also sell masks, but generally there are more fox masks.

In the first season of Friends, Yan covered her eyes with a piece of cloth. At that time, Natsume covered his eyes with a piece of cloth when he went to help him, in fact, in order not to have direct contact with the monster. For example, the animation says, "Don't look into the monster's eyes, otherwise it will be easily targeted."

Japanese culture believes that everything in the world is aura, and people and monsters also have communication, so some monsters will wear masks to distinguish them when they grow up. Like Natsume, after wearing a mask, those monsters can't smell his human breath. I think the mask should also have the function of isolating human breath, otherwise other monsters can't smell him.

However, there is also a saying that one's demon power is all in one's mask, but only limited to some small demons, such as teacher cat and little sister who likes smoking. If the masks of those little demons are destroyed, it is estimated that the demon power will also dissipate, which is equivalent to an instrument.

In fact, in the narratives of Natsume's friends, both small monsters and big monsters, Natsume's adult has become more and more gentle because of these monsters, and the cat teacher who is hard-spoken and soft-hearted has always been with Natsume's adult.