Women on a giant phallus at the Kanamara fertility festival. This is Japan’s best festival, and it’s coming up on Sunday April 6th.
Video of the festival: http://www.youtube.com/watch?v=SggvPrkoJUI
Shrine homepage: http://tomuraya.co.jp/wakamiya.htm (Japanese only)
There are other posts about the festival here:
2-3-16 Daishi Eki-mae, Misaki-ku, Kanagawa City, Kanagawa Prefecture. Inside the grounds of Wakamiya Hachimangu.
To get there, take the Keikyu line from Shinagawa Station. Transfer to the Keikyu-Daishi Line at Keikyu Kawasaki Station and get out at Keikyu-Daishi. It takes about 45 minutes and costs 580 yen. It starts at 10:00 AM.