The robotic system, called the Eco Cycle, stores bikes 36 feet underground. It can store 204 bikes at a time.
To use it, you need to attach a chip to the front wheel of your bike that links to your Eco Cycle parking account. When you pull up to the Eco Cycle, it will recognize you're a paying customer. Simply press the button and your will be taken underground.
Bikes are so ubiquitous in Japan that construction company Giken had to build an underground system to store them.