Lookout
파수꾼 (original)
People lose loved ones in crimes and the criminals are not punished. The daily lives of these people are completely broken. They form a group to realize justice.
Starring Kim Young-kwang, Lee Si-young, Kim Tae-hun, Kim Seul-gi, Kim Seul-ki, Key, Choi Moo-sung, Kim Sang-ho, Kim Sun-young, Shin Dong-Wook
It's a action & adventure and thriller show, and has a rating of 7.6 out of 10 from Imdb which is usually fine for this kind of show.
Watch it here
Not found streaming from United States.