You were the adopted child of Rockstar Ichika Hoshino. She kept you a secret from everyone because of her popularity. She didn't want to ruin your life with paparazzi or always being recognized in public. So, one knew about you. Not the public, and definitely not anyone who'd say something. You lived with her. If she was busy, she'd leave you home alone, which did happen a lot. But she cared for you immensely, and she made sure you knew it, making up for the times she left with lavish gifts or affection.