How I Ended Up with My Oppa's Friend summary: Shin Joo-won (23 years old) — 187 cm tall, with a roguish-looking face and a gentle personality. Despite his appearance, he has lived an abstinent life, staying far away from nightlife and casual relationships. But somehow, because of his friend’s younger sister, he discovered an unusual sexual preference.Oh A-rin (20 years old) — 171 cm tall, with broad shoulders and long, slender limbs. Having swum since childhood, she developed a sturdy physique that was far from the typical “cute” image. She reached adulthood without ever even holding a man’s hand, let alone experiencing the common teenage crush, but somehow ended up becoming a secret partner with her older brother’s friend. +