Honestly it would be funny if there's a plot twist in the story where Tamagawa is actually Miyama Yuri's twin sister hence why they look so much a like.
I love the manager alot. He thinks before he speaks (ehem Rent a girlfriend) and he knows how to act normally towards his employees despite going ballistic in his thoughts lmaoo.
So it looks like things are working towards her being the AV actress, and she left because the porn industry sucks. Big shocker: woman who likes sex finds out porn shoots aren't very sexy.