Cold Female lead?

Greatest marriage

Coffee house

KBS drama special -->> Middle school student A

Jumong

Queen seo deuk

East of eden ( han ji hye character)

Kluen cheewit - thai ( yaya really cold at 1-5 ep the rest )

Empire of gold ( no romance)

Flames of desire

Sassy girl

My wife is a gangster ( Chinese lead female)

Maybe the legends?It just finished airing,and the female lead is calculating and very focused on revenge.

Crown Princess from Thailand

Personal Favorites

(Korean)

Hotel del Luna

It's okay to Not be Okay

The Uncanny Counter  (ongoing -> Hana is cold and tough, kicks some serious ass. Romance is not the focus)

(Chinese)

Miss Gu who is Silent (romance is there but definitely not a focus)

Twisted Fate of Love (Ongoing -> Female lead is a general who is mildly cold but mostly towards the ML, the male lead is a cruel person who gives tsundere a whole new definition)

(Thai)

Girl From Nowhere (This series is DARK dark, so I recommend it to a few who are willing, but honestly the hardest part is getting past the first episode. Every episode or two is a new story with one constant, that being the FL. Cold, calm, calculating and without any feeling. Perfectly comparable to the little devil on people's shoulders that tell them to give into their desires. You'll learn what else after episode 2. Romance is at a 1%) Season 2 is coming soon