J's voice actor : Korean name - 김환진 = Hwan jin Kim
This is link for his interview.
He's been voice actor for around 40 years. He has taken rolls in various places.
Blade and soul - MMORPG game
Dragon Ball - Animation (Dubbing of course)
Closers - MMORPG game
Misteltein's voice actor : Korean name - 안현서 = Hyun seo An
This is link for her interview.
She has started her career from 1994 in Korean TV channel called 'Dae gyo'
Will this be enough