When you use public transportation in Japan, you often see people with masks.
In winter, people wear masks, so they don't give flu / cold to others, or they try to prevent from catching them. You can't really avoid flu / cold by wearing masks, but at least you care!!!
In spring, people wear masks, as many of them (me, too!) have pollen allergy and trying to prevent them.
When you are in Japan, stop by the drug store to check out the mask section. You'll be amazed how many kinds there are. There are some cute ones for kids!
