Anyway, I'm sitting here with paypal/credit card in hand, ready to donate. I have rudimentary understanding of Japanese, but I am ready to donate as soon as I know what I'm getting into.
Minimum payment is 10,000 yen. You'll get a wristband for your efforts. They may not accept non-Japanese donations though, I'm guessing there are taxation and other issues involved that they haven't been able to resolve yet as they mention it took them time sorting it out for Japanese donations.