If you are asking about masks now (in February and March every year), it is because of hay fever caused by cedar pollen. It is said about 20% of Japanese.
Flu masks are a part of everyday life in Japan, and they're worn for a plethora of reasons, including avoiding catching/spreading colds, warding....
Masks japan - tourA mask as a women's fashion accessory is often a Japanese veil - a tease for men who dream about the cute face underneath it. Of course it's not perfect. People certainly stare at you. If there's anything medical about them, it's the placebo effect in action. Maybe to stop drool?
Masks japan tour
We are working to restore service. I want to kiss you.. I'm American and have been looking at reusable masks online. Hence the masks, the convenience store automatons, the sour "leave-me-alone" faces on the subways, and yes, even the low birthrate Japanese people I know must be unique then, because they have friends, certainly aren't lifeless machines and don't have sour expressions. Oh, and the gun.