The plot of this movie involves Lupin and his gang being in a submarine for twenty minutes, with little to no conflict. It's immensely boring. After this, the movie takes place on an evil guy's militarized headquarters in a jungle. The evil guy wants the submarine so he can fire nukes at people.
Lupin, Jigen, Fujiko, and Goemon at the very least are treated decently in this. They act like their usual fun loving, money loving selves. One plus side in this very generic movie, is that the Lupin gang end up being nicer to each other than they often do. Fujiko is especially nice in this one, and of course she brings that sex appeal to the table, which helps. These classic characters are the best part of this story.
Inspector Zenigata is a complete joke in this one, he gets no respect. He's been taken off the Lupin case, so he just gets drunk and depressed, and even hangs out with the Lupin gang. At one point he wears an apron and acts like the Lupin gang's butler. This is very out of character, and pretty much sacrilege, though I admit it's a bit amusing.
The movie does have an enjoyable action climax though, and a nice ending.
All in all, this is on the lower end of the Lupin spectrum. For me, it was worth sitting through for some fun moments between the Lupin gang. If you're not a Lupin completist, this one is very skippable.
