It's no wonder why Shohei Imamura's films are often considered a contrast to his mentor Yasujiro Ozu's films. Ozu's films are static, simple, about the polite middle class families with fairly uneventful lives. Imamura, on the other hand, was more like an amateur anthropologist seeking beauty or poking fun at a chaotic society getting caught up in corruption, nationalism, swindles of all kinds and its international relations.
Pigs and Battleships is a turning point in Imamura's career - from now on, his films all have that characteristic style of his. Fast pace and constant motion, characters living on the boundaries of society, a satirical view on the society itself, and many interesting camera techniques which make the movie feel alive and pulsing, unlike in traditional Japanese cinema up to that point.
In this movie, Imamura satirizes everyone and everything, from American soldiers, who are portrayed as dumb pleasure-seekers at the cost of everything, to Japanese (anti)nationalists, yakuzas and other opportunistic criminals, to the scheming Chinese gangsters who then in turn get swindled by a Hawaiian-Japanese fellow. This entire multi- cultural chaotic mess cannot be expressed more beautifully, and gives birth to one of the stranger insults I've heard in a movie ("International whore!").
Imamura's film, like always, doesn't follow a strict plot line, but instead focuses on as many characters as you can shove into the film's runtime. From the moral dilemmas of the protagonist's girlfriend, who longs for a better life in Kawasaki to the yakuza boss succumbing to illness. There is so much to follow and makes the movie constantly fresh. In a lesser filmmaker's hands, this kind of free-for-all, gambit pileup plot setup would be annoying and unfollowable, but Imamura's pacing salvages the entire story and holds it together, climaxing in the best scene I've ever seen that contains pigs and machine guns.
Another great thing about the film is how it's both comical and tragical in turns, but never does anything feel forced. During tragic scenes, there's never a cheap, tear-jerking musical accompaniment and pathetic lines of dialogue, same as how the funny scenes don't ever feel intrusive, they just effortlessly find their way into the movie's fabric. Every quality I've mentioned above is pretty much why Imamura is one of the greatest New Wave directors.