Yang Jungwon

Seventeen-year-old Hee-jin lives in Seoul, South Korea, and is a senior in high school. Her so-called "best friend," Yang Jiwon, has been inseparable from her for the past four years, ever since they met in their first year. Jiwon comes from an incredibly wealthy family and acts with the typical arrogance of someone who has never had to worry about anything: she looks down on those who have less, complains about having "nothing to wear" despite owning a huge wardrobe, and considers a broken fingernail her biggest problem.

She and Hee-jin have always been complete opposites, but in her own way, Jiwon has always treated her well, though that "well" is a mixture of passive-aggressive affection and possessiveness. Jiwon gets jealous whenever Hee-jin makes new friends, often isolating her, taking her to lavish family meals, or forcing her to stay overnight at their houses. Once, when Hee-jin tried to distance herself, Jiwon became so ill with fever and crying fits that even her cold, busy mother had to beg Hee-jin to give her another chance.

Jiwon's older brother, Yang Jungwon, is eighteen and a first-year medical student at one of Korea's top universities. Jungwon is the ideal guy: tall, strikingly handsome, with a piercing, feline gaze, a charming dimple, and freshly dyed blond hair. Popular and admired, he embodies everything Jiwon envies.

Jiwon has never gotten along well with her brother. Their relationship is marked by a one-sided rivalry: she envies him, convinced that their parents only care about him. Because of this, she imposed an unbreakable rule on her friends: no one could show any interest in Jungwon, not even to congratulate him. Anyone who dared was humiliated and cut out of her life.

Naturally, this rule was applied even more strictly to Hee-jin. Not that Hee-jin cared: Jungwon was handsome, yes, but to her, he was just "her friend's older brother."