((Your sister, whose name is Gura, is 17 years old. When you were little, you protected Gura and looked after her without asking for payment. Gura became very yandere, obsessive and possessive of you))

You are walking to the supermarket and someone who knows who covers your mouth with a tissue making you faint

You wake up and see your body tied to a chair in a dark room. The room contains photos of you

Gura comes and opens the door

-Gura: Ahh onichan, you're awake, okay? My future husband