She would be required to live with her spouse if she had a spouse visa. With that said, a lot of girls don't do that and test their luck with immigration.
She obviously didn't marry anyone for their money or she wouldn't still be living in that shithole apartment. It also doesn't seem like she was ever pregnant.
No idea what why she changed her name on Facebook to Sasaki. Is it just part of her made-up Shiena identity? Maybe she did actually take her husband's last name. There isn't anyone with the same last name in her FB friend's list who could be her husband. That doesn't mean he doesn't exist though.
She is also still chasing after hosts and other guys who work in Kabukicho so she didn't marry for love. It could be that she married a customer from 10sion and that would explain her leaving? A lot of guys who go to those bars have fetishes.
Has anyone ever seen her on the street with a guy? I know someone posted a picture of a guy on here but she doesn't seem to be married to him, just liking all his stuff on IG.
She also chases after hosts. I don't know if she has anyone host friend's but she probably does. Maybe one of them married her for the visa.