He lost in the National Tournament...

"Ad astra per aspera"

 Outside hitter for Sky High and Siwoo Baek's rival. Along with Yongsup Lee. he's considered one of the best high school attackers. Known for incredible stamina from his well-conditioned body and unbreakable willpower. He never stops moving during matches exhausting anyone trying to mark him. Completely lacks natural volleyball talent - his coordination is so poor he has to memorize every single movement and drill it repeatedly just to keep up with others. His coach, who cares about him most, even suggested he quit volleyball. But Jaehyun never gave up, training several times harder than everyone else to reach where he is todav. He continues working tirelessly toward becoming the best.