Both dramas are about found families, living close since childhood.. And friendships.

The timeline of both stories span many long years.

The leads relationship is organic.
A chilhood ‘oppa’ to lovers relationship.

In both dramas, one of the leads lost a sibling when they were young.

Both male leads have the same job later, I believe.
And he acts protective of the FL.

30 years of friendship to lovers stories
Writing full of wit
Great relationship between the leads and evident chemistry...

Hoping for LND to be as good as 9E2O to recommend in more detail...

Soft and romantic medical dramas.
Lovely chemistries
The dramas have that old warmth
Calm, meaningful and touching
The music feels similarly good
A great team of people working together

Rom-Coms
Girl likes boy first
And she tries to seduce him with her futile ways. But she becomes of a lot of help to him.
The man is a big fool who doesn’t realise who the one he actually loves until much later
...And cute stuff xD

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).)