An article of clothing originally intended to protect the head against heat and cold, but now worn primarily to be fashionable.
With the influx of Western culture during the Meiji Era of "Civilization and Enlightenment," many people in Japan started wearing hats. During the Taisho and Showa eras, many men regarded it an aspect of good grooming to wear felt hats when they went out (See photo), but the custom gradually disappeared.
Until the start of the 1970s, hats were popular among women as well; in fact, a new bride would almost always wear a hat when going off on her honeymoon. Berets like the one in the photo were popular, and many of the pavilion guides, or "companions," at EXPO '70 sported the hat "look." In present-day Japan, the hat culture appears to be on the decline.