Jimmy and Billy are reunited after being separated at birth. Billy decides to open up a marital arts school, to teach local kids. Billy is attacked by the shadow boss, who turns out to be his brother.

Jimmy captures his brother Billy and takes him to the Shadow Master. The Shadow Master orders Jimmy to lock his brother up and before Jimmy can do so, the Shadow Master turns on him. Jimmy sets his brother free and the two transform and escape from the Shadow Master. Jimmy is now one of the good guys.

Billy and Jimmy meet a powerful chi master named Su Lien and her sumo wrestler student named Tsunami. Su Lien is then duped into helping the Shadow Master reform his evil ways. When the Shadow Master hooks Su Lien up to a virtual reality machine so that he can drain her mind and steal her powers, Tsunami and the Lee brothers team up to rescue her.

The Shadow Master has come up with a plan to introduce a new drug to Metro City, called Oblivion. The double dragons, along with Colonel McReady, blow up the drug tanks and foil the Shadow Master's plan.

The Shadow Master begins operating an illegal fighting ring in a secluded area of Metro City. Sickle then forces a homeless martial artist named Vortex to fight in the tournament by holding a group of homeless children hostage. Billy and Jimmy must rescue the children and help Vortex before the Shadow Master can get rid of them.

Billy loses his memory when he is knocked into an ultra-magnetic field, and the Shadow Master tells Billy that he is his son. Billy then becomes the new Shadow Boss, and Jimmy and Marian must work together to bring the real Billy back before he loses his memory forever.

A one-armed mechanic and former police officer named Mike Pollard is duped into making new attack vehicles for the Shadow Master. When Mike realizes what he has done, he builds an attack car for the Double Dragons and helps them stop the Shadow Master.

Jimmy is framed for a bunch of crimes by a crooked police commissioner and is sent to Radica prison. Billy and Marian must free Jimmy before the Shadow Master can get rid of him using a deadly mutant named Hannibal.

The Shadow Master uses holograms to frame the Double Dragons for various crimes, and the Metro City police department dispatches a robotic officer named CLU to arrest the Dragons. The Dragons must prove their innocence while saving Metro City from a malfunctioning CLU.

Metro City passes a law banning hand weapons, and the Shadow Master takes advantage of the situation by illegally selling portable blasters. When a Junior Dragon's sister is injured in a drive-by shooting involving the illegally sold weapons, the Dragons work on shutting down the Shadow Master's weapon factory.

Kami, the master of the Komodo Dojo, recruits a Junior Dragon named Michael and uses him to attack the Shadow Dojo and take revenge on the Shadow Master. However, when Michael is captured, Kami must put aside her desire for vengeance by teaming up with the Dragons to free Michael.

The Shadow Master knocks Billy and Jimmy into a hidden section of the Shadow Dojo called the Abyss and imprisons the Dragon Warriors in his Shadow Mural. Inside the Abyss, Billy and Jimmy meet their mother, Marika, who has been trapped there since the brothers were babies.

The Shadow Master discovers a powerful Dragon artifact called the Eye of the Dragon which grants its holder the power of sight. Jimmy gets hold of the artifact, and it gives him incredible powers. However, it also begins possessing him. Jimmy is forced to choose between the artifact and his brother.