Drama with second female lead

She was Pretty - she fall in love with the male lead but is also the best friend of the female lead
Behind your Smile - she is in love with the male lead but seems to be a friend or saviour for the female lead
Rookie Agent Rouge (it is not the main story/ a Romance Drama - maybe doesn't fit exactly)

Cruel City
Doctors
High School King of Savvy
Iljimae
In Time With You
Joseon Gunman
Let's Eat
Love Rain
Oh My Ghostess
Queen for Seven Days
Suspicious Partner
The Heirs
The Legend of the Blue Sea
Tomorrow With You
Warrior Baek Dong Soo
Weightlifting Fairy Kim Bok Joo
You're Beautiful

Quartet (2017)