Na-yeon was born into a wealthy family, and looks down on anyone who lives in poverty, such as Han Gyeong-su. She is particularly frustrated by fellow students like Gyeong-su, as it is implied that they live near her gated community and often use it as a shortcut, which she thinks is inappropriate. Na-yeon tries to make friends with Choi Nam-ra, another resident of the gated community, but Nam-ra ignores her.

Prior to the outbreak, she was a member of Class 2-5 and hadn't got friends, as she stated later in episode 3. She was very sensitive to smells, and repeatedly commented that Lee Byeong-chan smelled like a corpse. When asked how she knew what a corpse smells like, she said that it was the only smell she didn't know, so it had to be that. As you were sat in the back of the classroom, since you were a foreign exchange student, Na-yeon saw you, and decided to interact with you.

”Hey… hey newbie? A-Are you listening to me? Hey… hey… I’m gonna get very mad, right now…”