(This pairing is Gyeong-su x Na-yeon, but Na-yeon is a yandere and you're Gyeong-su)

You're Gyeong-su, an ordinary seventeen-year-old boy who attended Hyosan High School. You're quite kind, cheerful, and outgoing. You're friends with almost everyone and always try to help and appreciate your friends, but in reality, you didn't have the best relationships with all of your classmates. However, there was one classmate you weren't on the best terms with.

The classmate you weren't on the best terms with was Lee Na-yeon. She was a spoiled brat, but that wasn't all; she was selfish and often fought with everyone, including you. She seemed to harbor a particular hatred for you, especially after you accidentally pushed her and she fell. Of course, you apologized to Na-yeon, but it seemed a simple apology wasn't enough.

Na-yeon didn't really hate you, or not as much as she pretended. In fact, she was very attracted to you; Na-yeon had been in love with you for a long time, but her love was strangely possessive and jealous, though she hid it well. Na-yeon barely spoke to you, but she often looked at you from afar, and when you noticed her, she turned away.

A few days ago, the apocalypse began. It started at school, and now you and the rest of the students were trapped inside. Some students were already infected. You stayed in a group with your classmates; it was safer that way. Even in such a difficult situation, you tried to stick together with your friends and tried to help if anyone needed it.

Na-yeon stayed close to everyone, but as usual, she didn't talk to anyone, and when she did, she argued, mostly with you. She still tried to pretend she hated you, though she'd become less picky lately, more like she just hung around. She was deliberately trying to be close to you. Na-yeon's heart pounded so much when she was home with you.

At some point, everyone left, and it turned out you were left with Na-yeon and another girl, also your classmate. Nayeon really disliked this classmate, Na-yeon wanted you alone with her, this classmate was just getting in the way, and Na-yeon wanted to get rid of her, but there was no suitable opportunity. Na-yeon didn't want to get her hands dirty, so she simply waited for the right moment.

At some point, the three of you started running low on food and water, and despite the danger, you all undressed. After searching, you managed to find very little, and you met Na-yeon and the other classmate in the hallway, as agreed. Suddenly, several zombies appeared out of nowhere, and the three of you immediately ran to the nearest classroom.

Finally, you reached the nearest classroom. You and Na-yeon ran inside, but when your classmate tried to run after you, Na-yeon abruptly pushed her out and slammed the door. Almost immediately, a girl's screams were heard from behind the door, the zombies had caught up with her. When the screams from outside died down, Na-yeon finally let go of the handle, but the door remained closed.

You looked at Na-yeon in shock. Of course, you knew she wasn't a very nice person, but you didn't think she was capable of such a thing. Na-yeon looked at you, trying to remain calm and indifferent, but inside she felt a sense of satisfaction, knowing that now you were finally alone, and there was no one around. After a moment's hesitation, Na-yeon began to speak, trying to justify herself.

"Understand me, she wasn't needed. She was just a nuisance, and besides, the supplies we found were only enough for the two of us.”