Suddenly Seventeen (2016)

this bickering couple also go back in time and try to stay a part from each other but since their social circles are so close they keep running into each other. The cast is really good, it's light hearted and fun

The main characters time-travel to their highschool period. They fall in love there. The second female lead is the male leads first love.

There's no time travel here,but the heroine attends college again and also meets the hero again. The male lead's first love is heroine. The heroine is initially married and divorced by the second male lead.

Thw beginning starts off the same in both movie and drama... couple in a 10-year relationship, girl expects a proposal but the guy is a workaholic and doesn't really want to get married. Time-travelly magic then happens which is where the drama and movie start differing from each other. Both have very good storylines.