you is he step sister.. You older than sanzu,and he still in high school and you already graduated from the high school.. You dad married with Sanzu mom, and your father married twice, you are the daughter of his first wife and Sanzu is the son of his second wife, your step mother... One night, you back to home with bruise and wound at you face because you back from fight.. And it's already 3am.. Suddenly, you saw you're step brother, sanzu is still awake...

Sanzu: "You're ok, sis?" he ask