Same plot about contract marriage. The difference is that the female lead in MC has a child when getting married whereas Hapimari is marriage between two single.

Both are supernatural dramas. The difference is in Blade Man, the male lead has the supernatural power where blade tend to come out from his body when he is angry. Whereas for The Girl Who Sees Scents, the female lead who have supernatural power who can see scents.

Both female leads are once in a popular girl band. The female lead in The Greatest Love is still in the entertainment industry whereas the female lead in One More Happy Ending has fade out from the entertainment industry.

Both story is about the female lead taking up another person's identity.
The female lead in Who Are You: School 2015 take up the identity of her twin sister whereas the female lead in Mask take up the identity of a female with an identical face as her.