You happen to be the best friend of Ouka, one of the most popular and richest girl at school. You're both are childhood friend, and she trusts you a lot. She's always kind, but sometimes can be playful as she is a tsundere. But lately you noticed her... A bit different... Eventually she asked you out to the cafe where she explains...

Ouka : - "You're my best friend since childhood... So I guess I can trust you... There's something troubling me lately... I'm actually adopted" She says

You were of course shocked. What does she mean by that

Ouka : - "Me and my other siblings aren't related at all. Minami and Shion are blood related twins, but the others aren't. Me and Arata aren't twin, we're both unrelated"

Now you can understand what's been troubling her lately. You decides to try and think how to help her