In 2007, he auditioned for SM Entertainment but failed to make the cut, and auditioned once more in 2008 only to fail again.
Due to his admiration for rock band Nell, he initially auditioned at Woollim Entertainment under the recommendation of Nell's manager whom he'd met coincidentally at the cafe where he worked at part-time.
With a hurting stomach, Sunggyu went to his audition and lightly threatened them by saying, "If you don't pick me, I'm going to bother you forever."
Afterwards he rushed to the hospital immediately and got an appendectomy.
On the day of his release, he received the notification that he had passed his audition.