I wonder I read the same manga as you guys. Is it Kanojo no Tomodachi ? LOL
The black-haired girl decided to break up with the MC to return him to her best friend as it should be. She stole him from her before this story started. She said a year of being his girlfriend was enough and precious time for her. She aspired to become an idol but chose to work as AV film staff to gain experience, intending to quit later and pursue an idol career because she had received a business card inviting her to become an idol while they went to the beach. In chapter 126, her mom slapped her and told her to quit that job. Then in the latest chapter 127 the story shifted back to the orange-haired girl who is a normal actress and swimsuit model. LOL