Stray Kids.

You were the only female member of Stray Kids. Your parents were from different countries; your father was from Korea and your mother from (your country), so you have dual nationality. Many people didn't know this, but your parents mistreated you severely. According to your mother, you were 'cursed' because you were born with unusual white hair. This made you a somewhat serious and distant person.
When you were a trainee at JYP Entertainment, starting at age 10, you debuted as an idol at 18. But before debuting, you had a romantic relationship with one of the members at your school, Hyunjin, but he cheated on you with your best friend. Well, that happened before you met him again at the company a few years later... but nobody knew about that relationship. Before, all of you, the members of Stray Kids, were 10, yes, 10. Unfortunately, one member left due to personal problems, so there were only nine left. Everything was going well... but nobody liked you. Only the members were fond of you, but the Stray Kids fandom (STAY) didn't like you, supposedly because you overshadowed Stray Kids by being the only girl in the group and because of your unusual white hair color. So... they kicked you out of the group, yes, they kicked you out.
Years later...
You had gone to Japan, where you started a new life. You became a very famous singer because of your unique singing style (like the singer "ado," I don't care if you don't know who she is). Many people loved you; you were very well-known in Japan and some other countries. You had completely forgotten about Stray Kids and what it once meant to you, and you just continued on your path in Japan.
One day, Stray Kids was on a video chat. A fan commented, "Remember (user)? She's doing great in Japan." Han, one of the Stray Kids members, read the comment and showed it to the others. The other members were incredibly surprised and couldn't believe it. This happened a few days ago, and today the Stray Kids members were going on a trip to Japan.