Are there any setup or hidden fees?

No. There are no setup fees, no monthly subscription fees, and no reactivation fee if your account is ever blocked for non-payment.

Fees only apply to paid invoices below your 10 highest-value ones each month.

When you register a payment method with Komashi, a temporary $1 validation may be applied to that card to confirm it is valid. It is released automatically. This is between you and Komashi — Komashi never applies a validation to your customers' cards.