Origin
Chang used to be a police officer on Hong Kong, China, but it has only been alluded to that he let several of his comrades die at the Star Ferry Port. The details of this incident are unknown, but he either left or was drummed out of the police. He would later join the Chinese Triad, and the Dai Lo trusted him enough to put him in charge of the Triad base in Roanapur, Thailand.
Creation

Mr. Chang (ミスター張, Misutā Chan) is a supporting character in the Black Lagoon series that was created by Rei Hiroe. The series first began serialization in Shogakukan’s Sunday GX magazine on April 19, 2002.
His first appearance was in Black Lagoon Volume 2 CH. 11 “Bloodsport Fairy-tale PT. I”.
Chang’s appearance is strongly based from the the films of Chow Yun-fat, such as “A Better Tomorrow” and “Hard Boiled”.
Major Story Arcs
Bloodsport Fairy-tale Arc
Someone in Roanapur was behaving reckless and was targeting the officers of both the Triad and Hotel Moscow. The fact no one could find the killers meant someone was hiding them. The various syndicates gathered for a meeting, but all present claimed no involvement. Word eventually came out the killers were a set of twins called Hansel and Gretel.
As Chang did some investigating, he shook down Rowan the Pigeon, the local strip club and brothel owner. What he learned was that these kids had been victims of some of the most perverse crimes imaginable. Meeting in secret, Chang brought this information to Balalaika, and he went to confront Verrocchio, head of the local Italian mafia and the only man who could be hiding them. Just as Chang arrived, the twins had turned on Verrocchio, then were trying to kill him. He defended himself until they ran. Both were later killer by Balalaika’s forces.
Goat, Jihad, Rock’ N Roll Arc

Chang and his organization came into possessing rather valuable documents they had stolen from a courier that detailed the plans of a terrorist attack aimed at the United States. He tried selling the information back to the Protectors of the Islamic Front, but they rejected his offer and targeted him. His local offices were soon the victim of a bombing. Chang hatched a plan to sell the information back to the US. He just needed to get them the documents. Chang sent out various decoy teams, but came to the Lagoon Company to deliver the real ones.
The Protectors of the Islamic Front attacked the office they were meeting, and Chang aided their escape, along with Revy. While he did shout out the code word they would need for their contacts, Chang was clever enough to radio them with the changed code once they were out to sea.
El Baile de La Muerte Arc
When Roberta, the killer maid, returned to Roanapur to seek revenge for her slain employer, Chang had a meeting with her young master Garcia and the Lagoon Company. Seems who she was hunting was a U.S. Black ops team called Grey Fox.Chang had hoped Lagoon Company would help Garcia find his wayward maid and return to their county before she caused trouble, but only Rock and Benny agreed to help.
Most of the syndicates wanted to stay as far away as possible out of Roberta’s path, but Chang was contacted by the C.I.A. through the Church of Violence. They swore that if the blood of any U.S. trooped as spilled in Roanapur, they would destroy Roanapur form the map. Chang then directed some of the effort from the safety of his offices through Rock. Unknown to anyone else, Chang had left a message for Roberta to help get her to the real target of Grey Fox in the Golden Triangle. This worked out in the favor of Chang and the Triad.
Powers & Abilities
Chang is a human with no extraordinary powers or abilities.He does have heavy combat experience and thinks with a level head even in the most desperate of situations.
Marksmanship
He is highly trained with firearms and shoots using a duel-pistol style of gun fighting. Even Revy admits to not being as skilled as himself.
Leadership
Chang is a highly effective leader that is respected among the Triad he holds command over in Roanapur. He also has a significant influence in the city of Roanapur.
Weapons & Equipment
Beretta M76

Mr. Chang’s weapon of choice are a pair of Beretta M76 Semi-automatic pistols. The Beretta is an Italian-made handgun. He keeps them in a duel pistol holder strapped to his belt at his back.
Other Media
Anime
Black Lagoon (2006)
The Black Lagoon animated series is a direct adaptation of Hiroe’s original manga. It’s produced by MADHouse Studios and Geneon Entertainment. The series first began airing in April 8, 2006. The series ran for twelve episodes, the last airing on June 24, 2006. It’s a seinen action series that is for mature viewers
Chang’s her first anime appearance was in Black Lagoon – Episode 11 “Lock’n Load Revolution”, which aired on June 17, 2006. His character in the Japanese series is voiced by Toshiyuki Morikawa, and the U.S. dub produced by Ocean Group is done by Trevor Devall.
The continuity of Chang’s appearance was changed from the original series. The Bloodsport Fairy-tale Arc was his official first manga appearance, but that was moved to the second season of the anime.
Black Lagoon: The Second Barrage (2008)
Black Lagoon: Second Barrage is the second anime series of the Black Lagoon franchise. The series was directed and produced by the same team who created the first season. The first episode originally aired on January 18, 2008. The series ran for twelve episodes, the last airing on April 11, 2008. The story arcs covered in this season are Bloodsport Fairy-tale, Greenback Jane, and Fujiyama Gangsta Paradise.
Black Lagoon Blu-Ray Omake
Chang makes several appearances in the omake shorts that were added to the blu-ray re-release of the Black Lagoon series in Japan. These were all based on the omake extras added to the Black Lagoon manga volumes. He appears in the gender swap short, and a brief appearance as Balalaika’s husband.
Black Lagoon: Roberta’s Blood Trail (2010)
Black Lagoon: Roberta’s Blood Trail is the third anime series of the Black Lagoon franchise. Though this series was produced by the same teams who had created the previous two. It was never created to be aired on TV. Instead, it was sold directly to the Japanese market as OVAs. The entire story follows the El Baile de la muerte story arc from the manga that was told in Volumes 6-9. The first episode originally released on February 15, 2007 on Blu-ray and DVD. Production delays after the release of Volume 2 would result in delays of Volumes 3-5 by two to three months.
At the 2010 Anime Expo, FUNimation announced they had acquired the license for this series and were initially intending to release the series in 2011, but production delays that held back several of the Japanese episodes pushed back FUNimation’s plans. They eventually released the series in the US in 2013.