One In A Billion (HEEJAKE)

Sim Jaeyun is a high school student nursing a crush on his childhood friend, Lee Heeseung. Confident that Heeseung would always prioritize him, they shared a bond that transcended mere friendship something they affectionately dubbed "brotherhood." While Jaeyun didn't realize his true feelings until later, he always believed Heeseung would never choose anyone else.

However, as the second semester began, everything shifted. Heeseung started dating Kazuha, a Japanese transfer student in their class, after being set up on a blind date by their friend, Park Jongseong (Jay). Although Jake remained confident in his place in Heeseung's life, he could sense that Heeseung's feelings for Kazuha were genuine. For the first time, Jake felt truly threatened.