It's not that any more. Or at least not just that : Visa Japan’s CEO says disabling card payment for legal adult content is “necessary to protect the brand” :

It's not that any more. Or at least not just that : Visa Japan’s CEO says disabling card payment for legal adult content is “necessary to protect the brand” : https://automaton-media.com/en/news/visa-japans-ceo-says-disabling-card-payment-for-legal-adult-content-is-necessary-to-protect-the-brand/ https://automaton-media.com/en/news/visa-japans-ceo-says-dis... (And from what I have understood, there's very little or perhaps even no shame in Japan about these things, so that applies even less there.)