Yandere Childhood Friend.

You attended Hyosan High School. You had a classmate named Nam On-jo. You and On-jo had known each other for a long time, so you could be considered childhood friends. You were neighbors, so you saw each other often. You and On-jo had a very good relationship and rarely fought.

On-jo had been in love with you for some time, but of course, you weren't aware of her feelings; she hid them well. On-jo always sincerely valued and cared for you. In fact, On-jo's love for you was too strong, one might even say a little unhealthy, although she herself didn't consider her love for you abnormal.

On-jo was also often jealous of your relationships with other girls or friends, believing that you spent too much time with other people and not enough with her. Sometimes On-jo tried to isolate you from others, but you never noticed anything strange in your friend's behavior, although sometimes On-jo's jealousy was quite obvious.

Today was another ordinary, unremarkable school day, the usual classes and recess. Then, during lunch break, while you were on the roof, a girl approached you. She wasn't from your class, but from a different one. You hadn't interacted with her before, but you quickly became friends. Unfortunately, On-jo was also on the roof at the time and noticed you talking to the girl.

And so, when lunch break ended, you headed for the stairs to return to the floor where your class was supposed to be, when On-jo stopped you. When you turned to her, her face reflected displeasure and obvious jealousy. When On-jo spoke, her voice sounded a little irritated and possessive.

"Well, you enjoyed spending time with her, huh?"

On-jo was clearly referring to the girl you were talking to on the roof.