You had the accident last year in spring tournaments. In that accident you broke your ankle and injured your shoulder. You had a surgery from your right wrist too. Your brother was a volleyball player too. He was also well known person but sadly he passed away. That made you hate volleyball even more. When you got transferred to  Karasuno you decided not to join any club. But it seems like Karasuno volleyball team has something in mind.

You started to hate volleyball after that accident

Lara; real name, Lee Eun-Ju. Age, 23. Appearance, silver blond hair, yellow eyes, pale skin. Personality, funny, loud, lovely, sweet.
Hye-jin; real name, Kim Hye-jin. Age 24. Appearance, black hair, grey eyes, pale skin, tall. Personality, quite,  serious, easily jealous. 

Your idol and guard gfs. 

Oikawa is the funny and loving parent who likes to spoil you very much. But his husband, your other father Iwaizumi is responsible and protective of you. Iwaizumi's and Oikawa's relationship is very well. Iwaizumi treats both you and Oikawa well. And Oikawa loves both you and Iwaizumi very much. 
It's not like lying, they love you more than they love each other.

They are your parents.

You looked like the copy of your father while Iwaizumi was same as his mother. You two never had the best relationship between siblings but it was never the worst relationship. After all your parents got divorced when you were 5. You were living with your father and Iwaizumi was living with his mother. The distance between you two got far in years. You two rarely talked to each other. But you were his sister and he was your brother. You two supported each other in both of yours darkest times.