Shinya Kogami is a 28 year old man who previously worked as an Enforcer at the Public Safety Bureau Unit One. He is the hero of TV anime season 1 and the manga, Inspector Shinya Kogami.
Kogami is a highly skilled detective who, because of past events, works as an Enforcer for the MWPSB. His ability to solve cases quickly makes him a valuable asset to Unit One, to which he is assigned under his former best friend, Nobuchika Ginoza. When working, Kogami always keeps a level head, no matter what situation he's in without letting emotions cloud his judgment. The way he deals with investigations leaves even the best Enforcers impressed and appalled, as he usually uses risky methods to solve them. However, despite his mostly serious personality, Kougami has a sense of humor and finds it amusing to tease rookie Inspector, Akane Tsunemori, especially about how she once shot him with a Dominator.
Three years ago, while Kogami was still an Inspector, he developed a strong bond with his Enforcers, one of whom was Sasayama. When Sasayama died a horrible death while on the job, Kogami's emotional attachment and resulting feelings caused his Coefficient to rise and his demotion to Enforcer. Kogami is shown to have some wild tendencies that may have been encouraged by Sasayama (e.g. when he deliberately provoked Yuji Kanehara from the Drone Factory Murders case).
As the series goes on, Kogami begins to suspect the weaknesses of the Sibyl System and learns that Sibyl will not help him get revenge. This is what causes him to turn against the MWPSB and go into hiding to find Shogo Makishima himself.