Using and exploring a character's fears can be a powerful tool in storytelling. Not only seeing the character's fear but also their friends' reactions to the situation makes this a great whump trope.
Some examples in bromance heavy shows include:
A balloon's landing (the only movie on the list)
Tian-Yu's fear of the dark
Anti-fraud league
Mi-Ruo's fear of dogs
Justice in the dark
Pei-su's (self-induced) fear of blood
Reunion: the sound of the providence
Wu-Xie's fear of killing his best friend (a theme throughout all of the different adaptations really)
Live surgery room
Su Yun's fear of performing surgery again
The way home
He Jia Hao's fear of water (dragon boat racing mainly)
Unnatural fire
Shen Ye's fear of dogs
Bright time
Lan Jinghui's fear of the dark