Peephole

There are so many similarities!
To start with
The dead twin-sister replacement.
A very protective 'older brother'.
Fake siblings.
Leads working at the family company.
And more...

Entertaining big families that come close to heart.
The way both dramas deal with family-only dynamics is peaceful.
Full of comedy.
Heart-filling romances.
Double in-law couples.

I thought of one as I watched the other.
Family members of all ages.
Stories tackling their issues.
Good comedy present.
Three daughters in a family and their love stories.

The keyword is 'family'. There is nothing outside it in these dramas. Which is the nice thing. The realistic approach, fun family dynamics, big families.

For many reasons, the character Hyun Shi Woon in BMDF gave me strong vibes of Lee Sang Yi's character in OA.

Villain free family dramas that are purely big family dynamics, ups and downs, with the usual side couples, and peaceful fun.

The same mother in both dramas, three daughters, finding parents, an old bickering couple on the side, and lovely romances.

The romantic melodrama, the soft colors and dimmed atmosphere, and the subtle love.
Siblings, friends, and work life around the main and supporting characters.
Toned down and slow melodramas.

Same writer and same director kbs1 dailies.
An adopted child involved.
Many common supporting actors.
A writer supporting character.
A salon opposite a restaurant.
(Bonus: the main actors in BML resemble the actors in HFS: Yang Byeong Yeol (BML) resembles Yoon Sun Woo (HFS). Nam Sang Ji (BML) looks a bit like Lee Young Eun (HFS). Cha Min Ji (BML) looks a lot like Na Hye Mi (HFS).)

Birth secrets,
sword fights, some sorcery
rising to power,
FL and ML joining forces,
good writing, excitement
historical fictions

Both dramas show the lives of Joseon people during the Japanese colonization.
The struggle against foreign power to protect own's country.
Very intense and interesting dramas

If you are interested in how did Joseon come to that state in Mr. Sunshine, watch Nokdu Flower to know the story.
The events of Japanese colonization start showing in Nokdu Flower and we see how people lived after that in Mr. Sunshine.
What starts in Nokdu Flower continues in Mr.Sunshine as the independence army.
History, rebellion, sacrifice, patriotism, betrayal, and war. All of them are a continuation of each other in these dramas.
The characters in these dramas play similar roles too.
Not to miss if you are interested in the history of that era.
From Nokdu Flower in the 1890s, to Mr. Sunshine in the early 1900s.

Son Sukku looks like Jo Seung Woo (I had to. But it is more than appearances). Both are Gu 'sajangs' with that kind of personality.
The dramas slow vibe, music, directing, etc.
The romantic relationship in My Liberation Notes, and a similar one in Life only it was very subtle.
Following lives of multiple characters.
Greatly written.