A young Taiwanese assassin codenamed "Glass Heart" committed suicide by jumping off a building, and her heart was pierced by metal fence. Miraculously, her life was saved by heart transplantation. During her recovery she began to experience strange dreams, which lead her to Japan looking for the donor of her heart, who happens to be Kaori Makimura, former partner of City Hunter Ryo Saeba. The author mentioned in the first tankoubon volume that Angel Heart only shares the same characters of City Hunter but not its continuation. The events are all parallel universe, therefore it has nothing to do with City Hunter.

The film follows Jungle Pocket, who wishes to participate in the Triple Crown Classic race, which can only be run once in a lifetime. She faces rivals Agnes Tachyon and Manhattan Cafe.

Two years have passed since the end of the "Martian Successor Nadesico." Akito and Yurika have disappeared. The Jovians and the Earthlings have joined forces and Ruri is now captain of Nadesico B. As the popularity of Boson Jumping grows, a vast transportation network has been developed. Dubbed the Hisago Plan, this network of Chulip portals holds the answers to the mysteries behind Bose particles and their power. If those secrets should fall into the wrong hands, it could mean big trouble. And big trouble there is. A Martian splinter group has launched an offensive, leaving the United Forces befuddled and desperate. So much so, in fact, that the former crew of the Nadesico is called back to active duty for a special unsanctioned mission-to save us all. Does this menagerie of misfits have what it takes? Who will win the race for the Boson technology? And what the heck happened to Akito and Yurika?

In an alternate 21st century, the robotics industry undergoes a period of rapid advancement worldwide. By the year 2050, Japan has firmly established itself as the leader in robotic technology and manufacture with Daiwa Heavy Industries. As the technology evolves to include robotic enhancements to the human body, the blurring of the line between man and machine triggers a sudden shift in world opinion. In response, the U.N. passes a unilateral ban of further research and development on robotics in 2067. Japan fiercely objects to this ban, but is unable to prevent its passage. In protest, Japan withdrew from international politics and chose to pursue a policy of high-tech national isolation. While only trade continues, Japan disappears from the world scene. Ten years later, a series of bizarre incidents lead the American technology police agency SWORD to believe that Japan has concealed extensive development of banned technologies through the use of the RACE network. SWORD dispatches a unit of special agents to infiltrate Japan and gather intelligence on the country. Vexille, a veteran agent among the group, uncovers the horrifying truth behind the ten years of isolation.