Kameido Tenjin's birds for good fortune
Usokae-shinji - January 24 and 25
Kameido Tenjin Shrine （亀戸天神社） is known as a shrine for people who wish for success in their studies, like passing exams. On January 24 and 25, the shrine has a special event, the usokae-shinji （鷽替神事）. Similar festivals are held at a few shrines in Japan, in Tokyo also at Yushima Tenjin, January 25. On this day, people bring small lucky charms here and exchange them for new ones. The charms are carved in the shape of a bird.
The Lucky Uso Bird
There is a small bird, a bullfinch, that is believed to invite good fortune. In Japanese it is called "uso". Another Japanese word "uso" means lie. So when you exchange the uso-bird from last year at the shrine for a new one this year, misfortunes become a lie and the new uso charm invites good fortune in exchange.
Carved wooden birds are available in different sizes, maybe depending on how much good luck you wish for. The shrine also sells small uso-charms in the forms of cards, whistles and bells. All of these are only sold during the two days of usokaeshinji here, January 24 and 25.
Kameido Tenjin is located in Tokyo's Koto-ku, within 10-15 min walking distance from the Kameido and Kinshicho stations on the JR Sobu line. Many restaurants and cafes are located around the stations. The Metro Hanzomon line passes through Kinshicho as well, the next station is Oshiage at Tokyo Skytree.
More about Kameido Tenjin Shrine here http://www.kameidotenjin.or.jp/english/index.html