In both (movie & the series) the main characters are;

1. a police officer/detective
2. the 1st characters „helper that nobody can see“

Both also have: great action scenes with impressive fight-choreographies, a police case with a deep story and a lot of plot-twists, easy-going humor with a character that is the definition of a silly-goofy mood, great character development, a gril-boss character… I can be here forever tbh.

Bad and Crazy is simply Korean, less-gay, 10 hours longer version of this movie