Saisen Bako (賽銭箱, contribution box). Saisen is the money contributed to the God or Buddah and Bako (Hako) means box in Japanese.
When you go to a shrine and make a wish, you first put a coin in Saisen Bako then clap your hands twice and bow once then wish your wishes, not at loud but in your mind.
Depens on the Shrine, the size of the box are distinct. The photo below is the one at Meiji Jingu (Tokyo). Since they have so many visitors, of course they have a huge Saisen Bako. Sometimes, people throw the coin as they can't get close to the box, and it may hit your head if you are unlucky.
