I am looking for dramas with such relationships between the main characters.

On #6, Mad For Each Other.  It's really good.

https://kisskh.at/79527-the-crazy-guy-in-the-district

2: Fall in love with a scientist; Love Me If You Dare 

• +1 My Roommate Is a Gumiho - 1 (university professor) / 5
• My Love from the Star - 1 (university professor) / 5 / 6 
• The Princess's Man - 1 (royal tutor) / 6
• The King's Affection - 1 (royal tutor)
• Secret - 6
• Coffee Prince - 4
• My Secret Romance - 4
• Something About 1 Percent - 4 / 6
• The Beauty Inside - 4
• Lucky's First Love - 4
• The Secret Life of My Secretary - 4
• What's Wrong with Secretary Kim - 4
• Noble, My Love - 4 / 6
• Bromance - 4
• Itaewon Class - 4
• She Was Pretty - 4 / 6
• A Poem a Day - 3
• Doctors - 1 (high school teacher) / 3
• Ms. Perfect - 4
• Suspicious Partner - 4
• Koi wa Tsuzuku yo Doko Made mo - 3 /6
• A Love So Beautiful - 6
• Hospital Ship - 6
• My Little Happiness - 6
• Hotel del Luna - 5
• Doom at Your Service - 5
• Meow, the Secret Boy - 5
• Bring It On, Ghost - 5
• Goblin - 5
• Gu Family Book - 5
• A Korean Odyssey - 5 / 6
• The Bride of Habaek - 5
• I Hear Your Voice - 5
• One and Only - 1 (master and disciple)
• The Legends - 1 (master and disciple)
• Princess Agents - 1 (master / trainee) / 6
• Her Private Life - 4
• The Eternal Love - 6
• Queen In Hyun's Man - 5 (only supernatural power = time travel)
• Live Up to Your Name - 3 / 5  (only supernatural power = time travel)
• Dreaming Back to the Qing Dynasty - 5 (only supernatural power = time travel)
• The King: Eternal Monarch - 5 (only supernatural power = time travel / travel between worlds)

1st

Doctors

3d

Dinner Mate

4th

• The Secret Life of My Secretary
• Itaewon Class
• Hotel del Luna

5th

• Hotel del Luna
• My Roommate Is a Gumiho
• Tale of the Nine-Tailed
• The Beauty Inside
• 18 Again
• Angel's Last Mission: Love
• Memories of the Alhambra
• The Uncanny Counter

6th

• Our Beloved Summer
• Love with Flaws
• My Name