later on the story she (jeong-seok, the glasses girl) will caught her boyfriend cheating and isnt studying and then she is broken hearted and MC is helping her. And yes, MC is sleeping with her. But later at the office, MC feels like their (all females that know him) behaviour changing, somehow they becomes sweet towards him. Like na-sori greeting him, etc. And there will be a new character, i think its the new head development (i forgot what's called, but i think it is the position from na-sori boyfriend's before), and later on its team leader turn chapter (at 97). So basically MC is loved by na-sori, team leader, jeon-sorin, jeong-seok but i think mc still chasing seok-young the receptionist girl.