Plaza is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

15 years ago, two gangs survived the competition at the Capitol plaza to overtake Seoul.

Gi Jun cut off his own Achilles tendon and leaves his gang, realizing shortly after that his younger brother has become the other gang's leader.

15 years later, after his brother's sudden death, Gi Jun is now searching for the truth aiming to uncover what has happened.