Female heroine who is emotionally mature

I love watching romcoms, but am sick of perky, optimistic heroines who are clumsy and honest to god, have the  emotional range of a 5 year old. I want to watch a fluffy romance drama , but I want a heroine who is actually  mature and intelligent. I'm talking about dramas like What's Wrong with Secretary Kim? and her secret Life      etc. I absolutely hate angst and when they push misunderstanding for filling up the plot, but also really like        cdramas but are open to all languages as long as it's english subs are available. Thank You!!

I would suggest Run On.  FL is strong, smart, and funny, despite a  difficult past .  The scenes where she goes toe-to-toe with the ML's politician father, and trades F-bombs with an arrogant American cinematographer are hilarious, and indicative of her mental strength and toughness.  

 Emaris97:

I want to watch a fluffy romance drama , but I want a heroine who is actually  mature and intelligent. I'm talking about dramas like What's Wrong with Secretary Kim? and her secret Life      etc. I absolutely hate angst and when they push misunderstanding for filling up the plot

• Encounter 
• Live Up to Your Name
• Search: WWW
• You Are My Glory
• The King's Affection 
• The Beauty Inside
• Witch's Romance
• Across the Ocean to See You
• Descendants of the Sun

She Would Never Know (2021)

 something:

You Are My Glory: Qiao Jingjing is serious towards her work and has expectations of herself and her partner. The drama is slow-paced, but it's a good story that explores their relationship from classmates to friends to a romance.

Let's Eat 2: Soo-ji is a good character. She suffers from low self-esteem and works towards seeing herself in a better light. The drama is quite light-hearted, and the male lead is an old classmate of hers. whom she doesn't really like upon meeting again.

Rookie Historian Goo Hae-ryung: Hae-ryung is a historian, and because she is a woman is faced with some obstacles because women aren't quite accepted in taking on the role as one. She has a romance a Prince.

I second the Rookie Historian recommendation.  It's funny because Shin Se Kyung was such a doormat in her earlier roles, but in the last two she's really stepped up and played strong women.  I couldn't get over her performance in Run On, she's strong, confident, funny, but also vulnerable and real.  Except for IU in My Mister it's probably my favorite FL performance.