From what I see, people don't understand the true meaning to it. One of the characters is called Yasuo, named after the voice actor of the original Lupin who died in 1995. He first started with the Green Jacket like how Yasuo in the movie is. This movie is to celebrate 40 years of Lupin the Third, what better way to celebrate than to reference the guy that help the character come to life? The plot doesn't make sense because it's supposed to reference all the Lupin movies and other things. If you "truly are a Lupin fan" then you would understand most/all the reference.There is a hidden meaning to it all, though it mostly concerns the future of the series and lore, since this was an original of Monkey Punch, can't say that it has a solid plot for sure. But if you're well versed in the World, Lore and History of Lupin the Third and you want more lore, see references, or have a laugh at the jokes, I highly recommend this movie. As a fan of Lupin, I enjoyed it from beginning to end, though I recommend you watching it more than once to fully see what's going on. That is all, thank you for reading.