The story starts with the mysterious disappearance of the real ArsÚne Lupin III. Since then, people all around the world have been claiming to be him, by dressing as him and committing various grand-scale thefts and crimes. One of the impostors, however, is arrested in Tokyo for shoplifting: since he has tarnished the image of Lupin as a master thief, all the Lupin imitators go to the rescue. Most of them are promptly arrested by the Japanese police (led by Inspector Zenigata of Interpol) as well. Some of the copycats, however, are better. And among ''them'' are two that might be considered the "real" Lupin.
Enter Yasuo, a young cook and pickpocket, whose lifelong ambition is to become just like Lupin. This is straining the relationship between him and his girlfriend Yukiko, a news reporter. Yasuo has the chance of his life when a mysterious old librarian, thought to be the most knowledgeable man in all things Lupin, gives him a green jacket and a Walther P38 gun, the symbols of his hero. He then decides to become Lupin by planning a crazy heist: Yasuo wants to steal the "Ice Cube", said to be an extremely valuable diamond, from the "Night Hawks" organization. However, at the same time, another Lupin, one who dons a red jacket, is planning to do the same thing, with the help of his lifelong partner Daisuke Jigen: this Lupin could be the "real deal", and Yasuo thinks that, if he can outsmart or defeat the guy in the red jacket, he can become the next true Lupin.
Red Jacket and Green Jacket have a duel in the rain, interrupted when a missile strikes the place and seemingly kills Yasuo. He is not dead, Fujiko saved him from the explosion, and promised to cooperate with him in stealing the Ice Cube. As long as she gets to keep it, of course. Yasuo accepts the 0/100 split, on the condition that she recognizes him as the "true" Lupin. With Fujiko's help, Yasuo breaks into the Night Hawks headquarters and discovers that the helicopter that shot the missile came from Night Hawks, and not only is the Ice Cube actually the prototype of a new source of nuclear power to be used in warfare, but also that Red Jacket Lupin (along with Jigen and Goemon, who destroys the helicopter, piloted by a Nazi-esque Lupin copycat) and Inspector Zenigata are there in the building as well. Red and Zenigata actually let Yasuo escape with the Ice Cube to prevent its further use in future wars.
The question of who will be the next Lupin is still not resolved, so one of the Lupin impersonators sets up a confrontation between Green and Red. The two meet on top of a building and after a Manga-inspired fight... one of them falls down. The OVA ends with one Lupin awakening on an ambulance and escaping right before Zenigata could stop him, and another one escaping on a car with Jigen, with the police warning of the arrival of a "new Lupin".