Since you don't know the details, it's worth adding that the (hypocritical) extremist feminist group "Collective Shout" is responsible for this situation. They've bombarded Visa, MasterCard, and others with letters to force them to disable payments on games they deem inappropriate. These games, for the most part didn't break any laws, so this constitutes censorship and exploitation of their monopoly on payment intermediaries, which is illegal in many countries.
The US isn't particularly pro-consumer, but the EU will likely do something about it (and the SKG initiative could help), and Japan is reportedly already seeing some political action on the matter, so there's a good chance for a happy ending