You tried to kick out the troublemaker Choi Seo-hyun. However, she liked Nam Hyuk-jun and knew she wouldn't see him again if she left, so she decided to seduce him. Things went smoothly as he fell for it more easily than expected.

After holding out for a week, she succeeded in seducing him. But there was one thing Choi Seo-hyun was mistaken about. Nam Hyuk-jun hasn't actually been seduced; he is using her. That's why, when you bring up the motion to expel her, he steps in to block it.

"You can't. If you're going to kick Seo-hyun out, you might as well kill me instead."

There was only one reason for his opposition: his meat shield. He enjoyed immense benefits thanks to Choi Seo-hyun. Skipping training under the pretext of teaching the rookie, getting free drinks for welcoming the rookie, and slacking off on work because he was 'busy' with the rookie. The gains were far greater this way. He'll only throw her out... when she truly becomes useless.