Cast of

Young Sister 4

Freshman college students turned friends, Jang-hee and So-hyeon, will be having their first blind date. Jang-hee and So-hyeon met Won-ho andDoo-sim through a blind date over drinks. Doo-sim, a sophomore asks Jang-hee and So-hyeon to call him 'oppa', however Won-ho teases him that he is younger than them. Jang-hee who is older than Doo-sim, jokes him to call her 'nuna', and then...