5 ), ▁In noc ent ▁Def endant ▁( 2 0 1 7 ), ▁Famil iar ▁W ife ▁( 2 0 1 8 ), ▁ ▁the ▁film ▁ ▁My ▁PS ▁Part ner ▁( 2 0 1 2 ), ▁and ▁Doctor ▁John ▁( 2 0 1 9 ). ▁ ▁Early ▁life ▁K w ak ▁T ae - ge un ' s ▁parents ▁were ▁both ▁educ ators , ▁and ▁they ▁expected ▁him ▁to ▁also ▁enter ▁the ▁teaching ▁profession . ▁But ▁in ▁his ▁s oph om ore ▁year ▁in ▁high ▁school , ▁his ▁father ▁bought ▁him ▁a ▁V CR ▁and ▁the ▁first ▁movie ▁he ▁r ented ▁was ▁Rain ▁Man . ▁D ust in ▁Hoff man ' s ▁acting ▁left ▁such ▁an ▁impression ▁on ▁him ▁that ▁he ▁decided ▁to ▁become ▁an ▁actor , ▁despite ▁his ▁father ' s ▁ob jections . ▁He ▁later ▁studied ▁Theater ▁and ▁Film ▁at ▁H any ang ▁University . ▁ ▁Career ▁▁ 1 9 9 9 – 2 0 0 2 : ▁Begin nings ▁Ji ▁S ung ▁first ▁aud ition ed ▁for ▁the ▁ 1 9 9 9 ▁campus ▁drama ▁K A IST , ▁where ▁he ▁met ▁screen writer ▁Song ▁Ji - na . ▁Song ▁took ▁an ▁interest ▁in ▁the ▁young ▁up start ▁and ▁wrote ▁a ▁new ▁character ▁for ▁him , ▁leading ▁to ▁his ▁acting ▁debut . ▁Upon ▁the ▁suggestion ▁of ▁his ▁then - manager , ▁he ▁began ▁using ▁the ▁stage ▁name ▁Ch ae ▁Ji - s ung , ▁then ▁decided ▁to ▁drop ▁the ▁surname ▁" Ch ae ," ▁and ▁became ▁known ▁simply ▁as