How does Japanese Ecommerce work?

[kenne]

I'm thinking of doing some Japanese site. But have no idea how the Japanese Ecommerce work...

I need to know:
1. How do the ecommerce companies give and accept payment?
2. Do they have something like paypal?
3. What percentage of people have access to online-payment methods, credit cards, paypal accounts etc.
4. Are these electronic payments accepted in business world?
5. Are there things similar to sedo, and parking in Japanese world?

Thanks for your input!
Kenne

Another thread mentions yahoo auction for domains, so that's a possibility.

Can anyone tell me how the yahoo auction payment is done? Do they use paypal?