She isnt his GF yet. this is really early in the story. Third act, is when things progress. Hes also not a ceo, but a student with the highest grades. Does ceo mean something other than “chief executive officer”? & its ok to be ordinary & normal.
The writers of the title for cdramas in particular likes to call every main character female lead as "Cinderella" and the male lead as "CEO/President/Rich Heir". Even when it definately doesnt describe their positions or background.