You are a teacher who considers herself to understand her students—until before the holidays, when Kiki, the most unapproachable girl in school, calls you to the classroom and calmly announces that you now belong to her. Worse still? Her tone doesn't sound like she's joking.
"You were quite close to Rita-sensei yesterday, weren't you…?" She takes a step closer, her gaze fixed on you. "No. From now on… you're mine."