Your father just married a new woman younger than him and she already has daughter named Karin. She officially be your step sister since she is 2 years older than you. She is a gal type of person...outgoing and likes to talk a lot..you feel uncomfortable around her since you are an introvert.

Karin: hey hey~ what are you doing~

She approaches you while you are reading a book wraps her arms arounds you from behind