Shinpei Mayama, the Rat Clan, Union Mama... the all-stars of assassination, from all over the world, suddenly come after Lupin. They're players in a new game started by the executives of Marco Polo: Happy Deathday. Ami uses her hacking to get Lupin out of trouble, but she's shot and injured in the process. With Jigen and Goemon also under assault, Lupin comes up with a plan to take out all the hired killers at once.

Fujiko smiles deviously as she points her gun at Lupin, when Zenigata arrives to save him and Ami. They get into the inspector's car which takes off, but it's soon attacked by soldiers who are trying to cash in the price on Lupin's head. Abandoning the car, they have to cross the desert on foot, a difficult task made harder by the presence of Zenigata!

After Lupin's publicized demise, Ami is taken in by Zenigata, who has been demoted to narcotics for aiding and then losing Lupin. Soon after receiving a letter from Goemon, Ami contacts Marco Polo and proceeds to their headquarters in order to work out a deal. Marco Polo's CEO, Chuck Glay, instead catches her in a deathtrap, threatening to kill her unless she spills everything about Lupin, including the whereabouts of the money he purloined from Marco Polo. However, this scenario is revealed as a trap set by Lupin for Glay and his fellow instigators of the Happy Deathday game, using Ami's hacking expertise and the aid of his associates Jigen, Goemon and Fujiko. Zenigata, who knew Lupin was too clever to be killed so easily, collars Glay for drug dealing, and Ami, inspired by her experiences, enrolls at a girls boarding school to catch up on the real life she has missed.

In order to save their family workshop from foreclosure, the younger brother suggests to his brainless older brother that Lupin may be the answer to their financial problem. They build a smart safe for the Greater Tokyo Bank which can only opened by someone with no brainpower, as a special challenge to Lupin, the world's greatest thief. Stung by the resilience of this obstacle, Jigen, Fujiko and Goemon begin to implement a sadistic sleep deprivation, beating and exercise regime to kill off Lupin's brain cells. However, at the publicized event of the safe's opening, Lupin instead consumes lots of blueback fish, boosting his brains so that the safe's IQ counter is overloaded and resets itself, thus opening the safe. While the contest ends in a draw, the brothers become celebrities and begin selling canned fish, recovering their property.

Lupin is hired by his old friend Gaston to steal a certain painting - a Picasso forgery ostensibly painted by Gaston's grandchild - from the vault of Mr. B, a compulsive art collector. Lupin succeeds in his heist, but discovers in short order that the Gaston who hired Lupin was an impostor, since the real one died a month ago, and that the painting is the hiding-place for a notebook containing information about high-level crimes hushed up by the French police, evidence which would topple a number of high-level personnages if its contents went public. For this, he and Jigen end up chased by the DSGE and Albert, an old - and unfavored - individual from Lupin's past.

At Gaston's grave, Lupin and Jigen encounter Camille Bardot, an ex-investigator with a phenomenal photographic memory and an old acquaintance of Gaston. After receiving a telephonic challenge from Albert, the three of them find themselves targeted by a number of assassins. Mortally wounded, Bardot reveals that he aided Gaston in copying the original black notebook in the hopes that, at the right time, justice could be served against the perpetrators, but in turn they were ruthlessly hunted by DGES director Guillaume for it. Realizing that Albert set him up to gain possession of the notebook, Lupin returns to Paris to challenge him; but despite his precautions, Albert gets the drop on him, shoots him severely, and recovers the notebook.

Before Albert's triumph is complete, Lupin is rescued by Jigen and Goemon, and the notebook is snatched from him by assassin-for-hire José and his minions. While recovering, Lupin reveals that Albert used to be his partner years ago but, not being satisfied with "small-time" thefts, turned away from Lupin to become the shadow ruler of France. Meanwhile, with the presidential elections approaching, José uses the book as leverage against the government, allowing terrorists to wreak havoc with impunity in order to swing public favor toward his patron, the right-winged election candidate Calvess. He also has his gang pursue Lupin and his friends because of their knowledge of the book's contents. With their respective interests at stake, Lupin and Albert join forces against their common enemy.