Female lead pretending to be someone else and Male Lead trying to prove that she is a fake. Both male lead and female lead are nice...

Common points between the two dramas:
- Japanese
- Chubby Female lead
- Positive Female lead
- Nice and Supportive Male Lead

MLs are very nice and are always the ones to help solve everyone's problems. The FLs both change quite drastically throughout the series. All of the side characters had relatively interesting stories.

In both shows a young female enters a widower's home and takes care of the man's three children. In MMJS, there is an added hidden identity plot point.

In both shows the female lead takes the male lead who was raised away from people back to civilization. With TSD the male lead lived on an island and the female lead purposely took him away from the island.

In both dramas the male lead has some psychological trauma caused by a past lover. The mothers of both look for marriage partners for their sons in hope that they could be healed.

In both dramas the male lead is connected to the death of the fiance of the female lead. In FFI, the male lead has the dead fiance's heart, while in CFY, the male lead causes the death of the FL's fiance. FFI has more comedic scenes.

Both have mentally handicapped female leads. Both have some comedy thrown in. In My Sister of Eternal flower, the protagonist's siblings each have their own side stories.

In both dramas the main characters look to an online community to help them with a problem that they are facing.

In both dramas there is a younger woman-older man relationship. The woman has some kind of sickness.

Both are Japanese and have marriage contracts and socially awkward male leads.

Similar rich person gets amnesia story. In Couple or Trouble, it is the female lead who loses her memory.