Usually on New Year's Day, people hold mochi-tsuki events near the shrines or governmental facilities.
You can participate in this event.
Entry fee money is 500 yen.
It is 10 minutes' walk from Shibuya Station.
①KODOMONOSHIRO
http://www.kodomono-shiro.jp
MAP
http://map.livedoor.com/map/?lat=35.6590833333333&lng=139.710611111111&name=&zoom=
Spaceman