Both male leads are involved with police and crime solving (one of them is a coroner, while the other one is a private detective) and have their own ways to uncover murders but they share one thing - they talk to dead people.

Both movies are directed by Hou Hsiao Hsien and depict clash between innocent children and darker world of adults.

Both Big Brother and The Man Who Kills Troubles are about soldier/mercenary turned teacher who do their best to educate youth using means they learnt in their previous careers.

In both productions a bunch of dirty cops, riffraffs and prosecutors use unconventional methods to take down powerful and corrupted politicians. Both have lots of violence, although Asura is slightly bloodier.

Both productions tell the story of people who 'died by accident', are reincarnated in someone else's body and have to take care of stranger's family.
Both protagonists did some morally questionable deeds in their 'first life' and get a second chance to right their wrongs.

Can't explain too much without spoiling stuff, but both dramas are about normal people and how interacting with murderers changes them. They give off similar, suffocating and dark vibe.

Both movies were directed by Toon Wang and tell the story of a group of mainland chinese soldiers who've come to Taiwan and adopted a child, forming a foster family where none of the members are blood related.

Both movies are early New Taiwanese Wave productions made by Chen Kun Hou-Hou Hsiao Hsien duo with Doze Niu cast as main character. Both stories focus on mundane life of youths and grave consequences of lack of communication between family members

Both shows tell the story of young genius officials who use their smarts to fight injustice and solve mysteries.

Both shows focus on military training of unique youths - in case of AMA it's a woman crossdressing as her brother, in case of Decoded it's a math genius

Both shows use the same idea of mistaken identity and employing a (not exactly qualified for this position) stand-in for a dead person.

Both shows focus on swapped identity and how leads cope with being forced to live with someone else's family and kids.