Do I need online banking for Yahoo auctions?

I would like to buy items from Yahoo Auctions Japan. I live in Japan and have a Bank of Kyoto account. Thus, I can do ATM money transfers (振込み).

I do not have a credit card or online banking.

Many sellers list Yahoo!かんたん決済 as their preferred settlement option. It seems this is only for credit cards and online banking..? Does this mean my regular bank account (transfer at ATM) cannot be used to pay unless I apply for online banking?

I believe that you need to sign up for internet banking service with your current bank. When you pay with かんたん決済, in the process you will be directed to your bank's log-in page, where you'll enter your online banking ID/password and complete the payment procedure.

Sellers who don't mind ATM remittance would list 銀行振込 (bank remittance) or their bank name among payment options. In this case they will need to give you all their banking details. If they use "かんたん決済," they don't need to do that, as Yahoo! Japan works as an intermediary.

I guess it depends on whether it's a store or an individual, but I see many sellers who have 銀行振込 listed :)