It's a special project commemorating the 30th anniversary of Hokuto no Ken.

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)

A mysterious man known as "the King of Death" roams the streets of pre-war Shanghai in this action-packed prequel to Fist of the North Star. Shanghai in the 1930s is a dangerous place. Foreign governments and Chinese factions have carved the city into different quarters, each with its own laws and government, and all rife with corruption. As the major powers vie for political control, the streets are left to local gangs. Life is cheap, and death is always near. In days past, one man walked these mean streets battling the forces of evil. He was known only as Yan Wang, "the King of Death." Few knew who he really was, but many knew that he was a master of Hokuto Shinken - Fist of the North Star - a lethal martial art. He disappeared years ago after dispatching the city's worst gangsters, and is now rumored to be in Japan. Various people have come to Japan in search of him, but who will find him first?

In the year 19XX, after being betrayed and left for dead, bravehearted warrior Kenshirou wanders a post-apocalyptic wasteland on a quest to track down his rival, Shin, who has kidnapped his beloved fiancée Yuria. During his journey, Kenshirou makes use of his deadly fighting form, Hokuto Shinken, to defend the helpless from bloodthirsty ravagers. It isn't long before his exploits begin to attract the attention of greater enemies, like warlords and rival martial artists, and Keshirou finds himself involved with more than he originally bargained for. Faced with ever-increasing odds, the successor of Hokuto Shinken is forced to put his skills to the test in an effort to take back what he cares for most. And as these new challenges present themselves and the battle against injustice intensifies, namely his conflict with Shin and the rest of the Nanto Seiken school of martial arts, Kenshirou is gradually transformed into the savior of an irradiated and violent world. [Written by MAL Rewrite]