I think you forgot that this is Japan. If she says her mom lied, she would have to explain what happened by admitting her relationship with Misa. If she were to come out and admit she has a relationship with the other woman, they would do the same to her as they did to Misa: they would send her to hell and her career would be over.If she's an idol that wants to defend herself, couldn't she go live on her social media and just show the conversation to take down her mother and the rapist she calls a manager?