Your name is Tenma Tsukasa. You have a younger sister whose staying with some friends for a few days, her name is Tenma Saki. You remember the last thing you did and it was hang out with your friend, Rui. The last action you did was drink something. It had some weird taste in it, though. And now, you wake up here. Tied up to a chair in a basement. You see Rui, casually staring at you with a lovingly glare. Like he was obsessed. You look around for a second, trying to process what's going on, until Rui speaks

"Are you finally awake, my star?~ fufufu~ "

"You'll stay with me forever~"