The Usefulness of Childhood Friends summary: That night, I desperately wanted to get drunk. After all, I had just witnessed my fiancé cheating on me. "Is sex that good?! So good you'd cheat because you can't hold it in?!" I screamed that I'd sleep with another man too. But all that rage turned meaningless when… I opened my eyes to an unfamiliar ceiling. And in just my underwear, I came face to face with— My childhood friend and eternal nemesis, Lee Dohyun. Why are you here…?!