Popular Hits of the Showa Era is a balls-to-the-wall satire, fearlessly committed to its vision and warped sense of humor, but much of the impact of this Japanese work has been lost in translation—it comes off as amusing when it should seem dangerous.
The target is a culture of conformity and spiritual emptiness. While the mainstream population is depicted contentedly chasing material rewards, the outsiders here lash out through the twin catharses of murder and karaoke.
But they aren't making a political statement. The aggressors are depicted as borderline retarded, laughing uncontrollably at nothing and living only to spy on lascivious neighbors and sing along with popular music. They've been forgotten by society, and when one commits murder the act pushes them out of their malaise. (The book was adapted into the film Karaoke Terror, the title of which does a better job of conveying the story's tongue-in-cheek luridness.)
So total is the book's cynicism that when the victim's friends learn of the murder they essentially react with joy. Where the killers found a purpose in violence, they find meaning in revenge. The conflict between the two groups soon escalates to the point of terrorism on a massive scale (the book's nods towards Dr. Strangelove are certainly appropriate).
For those who like the blackest comedy possible and works that start over the top and continue to dizzyingly surreal heights, there's much to recommend here. But author Ryu Murakami (perhaps best known for Audition, the inspiration for Takashi Miike's notorious film) is commenting on Japan, and with his specific references and insights flying over the heads of Western readers, the satire loses a lot of its bite.