While trying to rescue a cat, martial artist Ryo Sakazaki and his playboy best friend Robert Garcia unwittingly break into a jewel thief's apartment. Moments after entering, they witness the thief being murdered by a group of thugs. Despite fighting their way out and escaping, things go from bad to worse when Ryo and Robert learn that the thugs were working for Mr. Big, the biggest crime boss in South Town. Not only does Mr. Big believe that the two have stolen the "Eye of Sirius," a priceless diamond, but he has also kidnapped Ryo's younger sister Yuri, and is holding her hostage. Without the diamond and out of options, Ryo and Robert must fight their way past Mr. Big's men and save Yuri before it's too late.

The story takes place on a world 100 years in the future, a few years before Lisa and Lorna joined eX-D organization. The world where people drives computer-controlled electrically powered "AI cars" which automatically take you where you want to go. However, one AI car mysteriously start to run amok. Now Nina and Rei, as the main driver for ex-D organization have to solve the mystery behind the AI car with evil plot and trap awaiting for them...

Super-deformed version of Hokuto no Ken, Buronson & Hara Tetsuo's post-apocalyptic fighting manga. Note: The "DD" stands for "Design Deformation," since the characters are only "two-heads-tall." (Source: AniDB)

Sun God Apollo the brother of Athena is here to take Athena back to heaven and taking over the sanctuary. He revived the deceased gold saints and use them and a few god saints as bodyguards. But Athena did not obey him, Apollo had no choice but send her to hell. On the otherhand, the bronze saints are on their way to save Athena.