"The Name of the Operation is Chuushingura" note Also released in English as "Operation: Chushingura." Original air date of December 10, 1979.
The episode opens at a Kabuki performance of "Kanadehon Chūshingura", a famous play about The 47 Ronin. Meanwhile, echoing the play's scene less gracefully, the Prime Minister chews out a police chief, Asano, for failing to capture Lupin III. Asano goes after his superior in a rage, finally pulled off by Inspector Zenigata.
At the theater, Lupin, Jigen, and Goemon are in the audience, Lupin noisily enjoying his rice crackers while Goemon weeps at the performance. Jigen sends Lupin out into the lobby so Lupin can enjoy his snack without disrupting Goemon's reverence. There, an old man accosts the thief, identifying himself as Kira Uenosuke, who Lupin jokes must be a descendant of the shogun official who started the whole 47 Ronin affair. He confesses he also finds the play very boring and wants to talk to Lupin.
Back at police headquarters, Asano has found out he has been fired for attacking the Prime Minister, much to Zenigata's distress. Ashamed of his actions, he bestows Zenigata with the task of capturing Lupin to show the Prime Minister was wrong for accusing him of inaction against the thief. In the name of avenging Asano, Zenigata calls in every policeman at his disposal to help him find Lupin. He calls the operation "Chuushingura."
At Lupin's hideout, a boat in the harbor, the thief prepares a meal and drinks, and consoles Kira about his "ancestor's" poor reputation. Kira informs Lupin there is a treasure hidden by him. So drunk is Lupin he has failed to notice Kira's feet never touch the ground. Jigen, Fujiko, and Goemon, who have just arrived on the boat have, though they remain quiet. Lupin, intrigued by Kira's boast, offers to recover the treasure and split it with the old man, fifty-fifty. Satisfied, Kira disappears in a haze. Lupin is confused, but drunkenly blows it off. Meanwhile, Fujiko is nearly panicked by the ghost and wants to leave, but Jigen is curious about the treasure. The three agree they can't let Lupin know that Kira is really a ghost, since he's developed a good connection with the spirit and don't want to frighten either.
The gang begins looking by finding the location of the old Kira's estate, which turns out to be where the current police headquarters are. The gang plans their operation, using blueprints of the current building, but are unknowingly spied upon. Meanwhile, Zenigata tries to spur the police gathered into making a plan to trap Lupin. Some, however, think a direct confrontation is best, while others are in the operation only for the networking and money. The second group, nonetheless, comes up with a plan to lure Lupin to Police HQ with the help of Kira's treasure.
That evening and back on the boat, Lupin confesses he isn't feeling well and is reluctant to go after Kira's treasure. Kira appears behind him and leaves a "deposit" to show he is serious about the treasure: a ring with a royal seal on it. Lupin decides to make the contract official then, although he comments on Kira's cold hands when they shake on it. Kira explains he's a ghost, but Lupin has a good laugh, thinking the old man is joking. The rest of the gang watches in trepidation and amazement as the spirit vanishes before them while Lupin pounds the table in laughter.
Outside, in the thick fog, other boats approach, full of the officers intent on filling Lupin full of lead instead of catching him. They spring, announcing they will not take the thief or his gang alive. Rockets are fired into the boat before the police storm it. However, when they enter the main room, a gas trap springs to life, knocking the men unconscious just before the boat explodes. Zenigata, watching from the shore, is relieved the gang escaped, but one of his men says he should compose himself like Oishi, the head of the ronin. As they drive off, Kira watches them, remembering how much he hated Oishi.
The next day, the cops injured in their capture attempt, and conspicuously bandaged over their faces, enter Police HQ. From the kabuki theater across the street, Zenigata and his new assistant watch. Upon entering, the three cops, actually Lupin, Jigen, and Goemon, find a quiet room to remove their disguises; unknown to them, the room is bugged, and Zenigata hears of Lupin's plan to empty the station of people by lighting it on fire. Zenigata wants to go after them then and their, but he is reminded to remain calm and wait.
As night and snow falls, Lupin and his gang go throughout the building, planting devices here and there before returning to their hiding place. At midnight, smoke springs out from various places in the headquarters; everyone evacuates. Zenigata and his loyal men across the street prepare to attack, Zenigata insisting they wear samurai armor. In the basement, the gang drills into the floor, looking for the treasure and finally succeeding in finding a very small box with a very large lock just before the cops storm the building. Running into the smoke they caused, the gang becomes disoriented; when everything finally clears up, it reveals they have been completely surrounded by Zenigata and his men. Just as Zenigata prepares to attack, the lights flash around the room, and the spirit of Kira appears.
Kira scares Zenigata by making him think he is going to take revenge on "Oishi" for killing him. While Zenigata is scared stiff, a spiritual light enters the guns of the forty seven loyal policemen, causing their gun barrels to explode. Kira urges the gang take advantage of the situation and run, which they do.
At the resting place of the original Asano, Goemon opens the box with Zantetsuken as the gang looks on. The box's contents are revealed to be a pair of false teeth. The ghost is pleased; you still need them in the afterlife apparently, and as Lupin offered 50-50, offers him the top or bottom teeth. Lupin, admiring how he as been outwitted, tells the old man to keep them all. Dawn comes, and Kira disappears, bidding Lupin goodbye. Lupin still doesn't believe Kira is a spirit, and the gang tries to convince him. Fujiko suggests the gang forget the whole thing and go swimming. And so they do on a lovely Caribbean vacation.
This episode features examples of:
- Big-Lipped Alligator Moment: "Let's go swimming, Lupin!" *cut to fabulous tropical vacation!*
- Haunted Fetter: Kira's false teeth are what are keeping him from moving on. Apparently, false teeth still have their uses in the afterlife.
- Homage: To the story of The 47 Ronin, but updated to modern police and thieves.
- Kabuki Sounds: They're used throughout the episode to mirror and remind viewers of the Kabuki play.
- Meaningful Name: Asano is the name of the shamed samurai whose Seppuku spurs the original 47 Ronin into their plan.
- Title Drop: Zenigata pretty much says the episode title word for word when the operation is made official.
- Unfinished Business: Kira's reason for sticking around... he needs the treasure he seeks in the afterlife.
- Why Don't You Just Shoot Him?: Some of the cops Zenigata why he doesn't just do this Lupin and end their chase for good. Zenigata proceeds to read them the riot act.