One

Two complete strangers became strangers just because of one person who disguised as someone else

The tvN drama revolved around four individuals who want to make it big in their respective careers or so the promos promised. Start-Up begins with a self-made Han Ji Pyeong (Kim Seon Ho), who writes letters under the cover of Nam Do San (Nam Joo Hyuk) addressed to Nam Dal Mi (Suzy) after she is separated from her sister In Jae (Kang Han Na).