A lot of Japanese women end up doing porn because of money debt. It's the fastest way to earn money for them. In some cases they quit as soon as they hit their financial goals. In other cases, they escort on the side to earn even more money...this is usually by women that enjoy the sex work.
In some very rare cases a very wealthy man takes interests in the actress and offers her a permanent role to be his paid girlfriend/sugar baby. It pays a lot better than porn does and she only has to fuck one guy (ideally) on a regular basis.
My guess is some filthy rich dude has been pounding out her holes since she stopped performing last year. The reason why we never see anything about her on social media is because he doesn't allow her to be on it.