Hi everyone,
I wanted some recommendations for romance drama where the main male lead is serious or emotionally closed off (not necessarily rude. Though I don't mind the 'rude' aspect, it's been a while since I saw a 'jerk' drama). Someone like the male lead in 'We Married as a Job' or 'Another Miss Oh'
I find it really cute to see people with this trait fall in love. It's even more pronounced when the person they fall in love with is bubbly and charming, like the secondary couple (Wei Qing Yang & Yang Na Na) in 'Bromance'. Anyway, I hope I'll be able to find few such dramas :)
Thank you in advance!!
Tatta Hitotsu no Koi ---
Pride --- 

My Sunshine ---  
Scarlet Heart --- Historical 
Loving, Never Forgetting --- 
Too Late to Say I Love You ---  set in 1930's China ...  serious, Not emotionally closed off (the opposite, very loving and expresses it), but serious matters r more important than love.

A Love to Kill --- 
East of Eden --- 
Goong -- 
I'm Sorry, I Love You --- 
My Princess -- 
Prosecutor Princess -- 
Tree of Heaven -- 
You Who Came from the Stars --- 

The master's sun
Hana yori dango
Nodame Cantabile

Faith fits your description to a T, with a serious, emotionally closed off male and a bubbly female. 
Cheese in the Trap also has a serious, distant male lead, but the female's not really bubbly
Love Rain
You're Beautiful
Blood
City Hunter
The Master's Sun
You're All Surrounded
Beethoven Virus
+1 Mask (one of my faves!)
Hotel King
Les Interpretes
Murphy's Law of Love
The Girl Who Sees Scents
Waking Love Up

Try Love O2O, he's more serious.  The girl is not bubbly, she's kinda down to earth and smart.  It's one drama where she matches him well, while still being likeable and identifiable.  Not a bafoon or crybaby.  I loved it.  He's very sweet to her too, and falls first.  

Boss and Me is pretty much exactly what you want.  She's cute and sweet.  He's serious and a bit cold.  He falls for her first too and pursues her.  
Beautiful Mind
1% of Something
Oh My Ghost
oh defintely:

please love the useless me