Cherry Blossoms After Winter (2022)

Both series include a main character whose parents die, he is then adopted by a new family and later falls in love with his stepbrother. One of the stepbrothers in each of the series initially refuses the other brother's affection because he does not want to disappoint their family but after some time he surrenders. In both dramas, the parents refuse to accept the relationship at first, so the couple has to persuade them that there is nothing wrong about that.
HIStory4 has a darker vibe because one of the characters uses morally questionable means to get his stepbrother's love.

Childhood friends to lovers, short length BLs with a school setting. Both are slower paced and lovely.

Both are korean bls. While A first love story is super short but cute show, Cherry blossoms after winter is mini series. Both are super cute and have the trope friends-to-lovers or best-friends-love

They both are college bls. They are soft, healthy, super cute but while kieta hatsukoi is more comedic way, cherry blossoms after winter is slow-pacing

It is similar because both main couples have someone who is shy and someone who is more confident. Both have a cute vibe.

Both are cozy short Korean dramas, set in school at the beginning, and focusing on soulmates (DMN takes this in a fantasy way). ML initially seems distant to the other ML or the FL.

Cute characters.
Character development.
Much Better story line.
Beautiful scenery.
Blueming will become your favorite korean BL of all time for sure.

Both are cozy, short, romantic Korean dramas about a love story between characters who've known each other for years, with one secretly in love with the other.

both are Korean BL with Cute Good looking couple
both dramas have high-production quality
the couples have really good chemistry