If you use Fantia
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go in there, buy Bitcash card, it will give you code in form of JP runes, which you can slap into Toraona to get Toracoin, that can be use to support stuff in Fantia
there's plenty of payment method you can do here including Visa and Mastercard, but using those will charge quite the number of 3rd party fee, furthermore the price of the card is not same to current yen exchange rate, but this is the closest you can get rather than picking whatever Fantia recommend you