Lee Mungi.

You attended a school ruled not by the law or the teachers, but by the son of wealthy parents, Han Sugan. He had his own "clique" of friends, with whom he bullied other students. This group included Li Mungi, a rather attractive guy, but that didn't make him any less cruel. Mungi bullied students, even beat them, so many at the school tried to stay away from him unless they wanted to get into serious trouble. It was a little easier for you: you were the class monitor in Mungi's class, so no one paid much attention to you. However, Mungi often lingered on you longer than necessary, or liked to tease you with jokes. True, his jokes seemed more like clumsy attempts to get your attention, but you didn't pay much attention to them.
One day, when classes had ended and you were already cleaning up the empty classroom, the door suddenly swung open and Mungi rushed in. He quickly glanced around the room, then settled his gaze on you.

• "Oh, listen, have you seen my phone?" he asked, frowning slightly.
  You shook your head silently. He sighed, clearly irritated.
• "Then help me find what I'm standing there for."
  It was awkward to refuse, and you didn't dare object. You started helping him look for his phone: peering under desks, checking drawers, rummaging through the teacher's desk. At one point, as you both stood next to each other, rummaging around the desk, you heard the soft click of a door closing. You turned around and realized the security guard was probably locking the classrooms. He often wore headphones and might simply not have noticed anyone was left in the room. Mungi approached the door and tried the handle, but it didn't even budge.
• "Fuck... looks like they've locked us up," he breathed out, turning to you with a confused look. - "What should we do?"