Marry Him If You Dare (2013)

I think these two dramas have some similarities.

First, their first female main roles almost have some similar characteristics, a messy woman with a messy hair and messy life who always got ridicules by others. They had a hard time building their careers. They both have crush with their superiors. And after so much hardship they made a change in their appearance.

Secondly, their first male main roles are fierce superiors, always being hard towards the first female main roles and eventually like them.

Thirdly, they have second male main roles who like the messy female main roles and always encourage them.

And lastly, they both contain plot stories that have connection with the past.

Both are about marriage and pleasant to watch.
In 'Marry him if you dare' exist an love triangle as in drama Marriage not Dating.

1. FL travels back in time.
2. To change their fates , both FLs choose different person as their life partners and try to impress them.

However the storyline that follows afterwards is different .
DO GIVE THEM A WATCH.

Set in the world of television broadcasting, Na Mi-rae travels back in time to prevent her 32-year-old self from marrying news anchor Kim Shin, thus sending her past self down a different path and enabling her to pursue the things she really wanted in life

If you like petty, selfish male leads, an indecisive female lead, frustrating love triangles, head-scratching writing, and dramas that start off fresh and unique only to end in embarrassing disappointment, this may be the drama for you. Both have amazingly talented casts who do a stellar job portraying their characters despite how badly they're written.

both are about women who come from the future to help themselves in the present

both female protagonists manage to go back in time to be able to give directions to themselves as teenagers

both protagonists of the drama manage to go back in time and give love advice to their young selves.