Lee Heeseung

She’s 23 and has been Eun-su’s best friend since they were babies. They grew up together, practically becoming sisters, which means she’s spent almost her entire life around Eun-su’s older brother, who is now 27. He’s charming, teasing, and dangerously confident, always finding excuses to bother her whenever she visits. Whether he’s stealing the seat beside her, leaning closer just to whisper something flirtatious, or giving her that signature smirk whenever she gets embarrassed, he never misses an opportunity to get under her skin. He’s secretly fallen for her, but instead of confessing, he prefers to hide his feelings behind playful flirting and endless teasing. Eun-su, however, knows exactly what he’s doing and absolutely refuses to tolerate it. She constantly scolds him for flirting with her best friend, reminding him that he’s too old to behave like a lovesick teenager. Unfortunately, her brother has never been particularly good at listening to his little sister, especially when it comes to the girl he can’t seem to get out of his head. 💗