Large parts of the narrative are written in a strange stilted way, almost like a formal pidgin English with lots of sentence fragments. It may seem annoying to the reader at first, but there's a reason for it - this is how the Japanese speak (the grammatical structure of the Japanese language is very different from that of English or any other European language, a challenge that has produced many a legendary Translation Train Wreck), and the narrator of those chapters, Robert Childan, not only speaks Japanese but also imitates the speech of his masters when speaking his native English. The farther away we get from the Japanese sphere of influence (in Juliana's chapters), the more normal-sounding American English the narrative becomes.
Imperial Japanese occupation in the book is less oppressive and racist than it ever was during the war, to the point where it may seem as if the book is whitewashing Japanese atrocities. But the book is not set during the war: it's set in an alternate 1962, when almost two decades have passed since the war and Japanese culture has shifted and is beginning to liberalize — just as the USA's culture did in real life.
In The Grasshopper Lies Heavy, why does Britain win the Cold War? Because in an Axis Victory world, Nazi racial theories are going to be much more accepted, and an imperialist and racist Britain is going to be viewed better than a "degenerate" United States.
John Smith is planning to send his son into hiding, safe from Nazi eugenics policies, in Argentina.
Juliana encounters a family from Argentina who want to immigrate to the Reich States due to fear of a war starting in South America.
Printed on the broken baby's cup that Tagomi mends during his time in the alternate reality, is apparently the baby's birthday: "April 8th, 1962 ". The Japanese observe April 8th as the Birthday of Buddha.
The Nazis dropped an atomic bomb on Washington DC on December 11, 1945. This is exactly four years after Germany declared war on the United States in real life, and exactly 4 years and 4 days since the day of the real-life attack on Pearl Harbor. Appropriately, the Japanese and other East Asian cultures regard the number 4 to symbolize Death.
A Meta-detail included with the end credits of every episode of the series is the message, "The characters and incidents portrayed are entirely fictional," provided in English and German and Japanese, mirroring the characters and settings and languages in the series.
Attentive viewers will notice that the SS Headquarters in Manhattan is located in the same place the UN building stands in Real Life.
The I Ching is a significant plot detail in Phillip K. Dick's novel, but is considerably downplayed in the adaptation and directly referenced only with Tagomi in season 1. Then, when Juliana encounters Hawthorne Abendsen a second time, he fiddles with eight coins. In the novel, the eponymous character is also influenced by the I Ching.
The revelation in the season 3 finale that a person can only travel into a world where their counterpart is dead puts Tagomi's trip to the alternate 1962 in a new perspective. It answers why his double never shows up, and his wife mentions how he "wandered off into the fog" one night and wasn't expected back.
When Kido is locked in the gas chamber in Kempeitai HQ, it turns out that the gas tanks are empty. That may be because the Japanese stopped using the gas chamber after Admiral Inokuchi advocated 'a lighter hand'.
Kido arresting Yamori is very well planned. He knows he can't openly defy Yamori, who is powerful enough to lock up even the Crown Princess. Instead, he lures Yamori into a situation where Yamori will be fairly lightly guarded (the execution of Grand Admiral Inokuchi), and the soldiers there will be loyal to Kido. Kido waits until the soldiers have already loaded and aimed at Inokuchi, because at that point they will be less hesitant to turn on another high-ranking officer.
The Smiths have three children in the Nazi-controlled world, yet in the alternate world where the Allies won, Thomas is an only child. Nazi propaganda strongly encouraged large families among those it deemed racially suitable.
Fridge Horror:
The population of Savannah, Georgia is stated to be a bit over 80,000 in the show's reality. In our reality, the population was about 150,000 as of the 1960 census. The difference can easily be attributed to the Reich exterminating all non-whites.
Also fridge brilliance: There is a *very* good chance that such campaigns would have wrought chaos on the economy of the South.
Tagomi travels to a timeline where he is alienated from his family. His family regard him with some hostility, but do not question his presence. Later, we learn that you can only travel to dimensions where your equivalent is dead. This means that in Tagomi's alternate timeline, his family is so alienated from him that they didn't even realize that he had died.
In Joe's conversation with the police officer who helps repair his truck's tire in the first episode, we learn that the officer was a veteran from the Second World War. He mentions that "it's been so long I can't even remember what we were fighting for." Mere seconds later, ash from the local "hospital" begins to rain down. How quickly we get used to horror.
At some point, Alt-John will have been gone long enough that being on one of his business trips can't account for it, and Alt-Helen and Alt-Thomas will realize he is dead, with no idea how or why and no body to bury.
to symbolize Death.