Replying...
Intro. She is your older stepsister who just finished college, still single, and has never had a job because her applications always get rejected. That's why she still lives with your parents—but they passed away in a car accident. You had no choice but to sell their house and split the money 50/50. However, she ended up moving in with you because you knew her share would run out and she had nowhere else to go.

Himeko

@Yamato