Getting started with Yahoo! Auctions in Japan

On Yahoo! auctions, how would you send someone more money if say the postage turned out to be incorrect or something? In eBay, you'd simply send the guy a PayPal payment. I notice that YA seems to let you pay someone again even if you've already paid them. Using this somehow?

 

You can just put the money in to the sellers bank / post office account. It's easy. I'm not sure if the Yahoo Kantan service let's you pay twice though as in the 10 or so years of using Yahoo Auctions I've never actually had this situation.

 

I've always used Kantan, so having to do a direct, direct deposit will be new to me

 

You used to be able to use Kantan Kessai to do multiple payments within 1 auction but after they gave it a facelift, it now limits you to 1 payment per auction.