Misaeng- The main character looks up to his boss, who takes the position as the mentor.
Answer Me 1997- There is a strong brotherly bond in this one, but also a bond with a fatherly figure they share no blood with.
The Three Musketeers- The prince takes a low level officer, who is our main character, under his wing.
Warrior Baek Dong Soo- The main character forms a brotherly bond with the friends and trains under Joseon's greatest swordsman.
Ugly Alert- This isn't just about a brotherly bond, but a bond between family, even when they aren't blood related.