There are no additional fee incurred when processing a refund for credit card, as well as Bitcash, Netcash and Nanaco payment methods. KOMOJU will refund the entire amount the customer paid in this case.
For other payment methods, work is required by our support staff to issue refunds. There are also additional fees for wiring money back to users here in Japan. To cover these costs, we charge a 600 JPY refund processing fee for non-credit card payments.
Note that we do not return the original payment processing fee to the merchant when a refund is made (for any payment method, including credit card / Bitcash / Netcash / Nanaco).