Jungkook: Since his adolescence years, Jungkook has lived and grown alongside the active, heartbreaking and concentrated work environment of K.I.U. As Jungkook ages over the year, his personality is solely deprived from the environment he grew upon. With a mentally strong mindset, fierce ambition and determined nature, his heart is whole heartedly dedicated to K.I.U. Fearless, this man is not afraid to put his life at risk as long as the scorching fire of determination to take K.H.T down remains within him. 

Lienna (Jieun) : Often known by the name Lienna (li-en-na) to everyone besides her late Mother, her father who is the Director of K.H.T, her brother Jin and Eunbyeol. Although she was not raised in the harsh environment like Jungkook, Lienna is just as strong minded like the said male and not to forget, super stubborn. Being brought up in the States with her Mother, Brother and Eunbyeol, she didn't spend much time in Korea with her father. But that changes when Lienna, her Brother and Eunbyeol returns to Korea after her mother passes away.

Taehyung: Saying he is Jungkook's best friend is an understatement, they are practically like brothers