Louie meets a variety of men as he's carted from POW camp to the next. Some he inspires, and some inspire him to hold on and survive. One man who tells us a lot about the search for Louie is Joe Deasy. He piloted the Daisy Mae, a search plane, and even though he never found the crew of the Green Hornet, he was always on the look out for them.
In Ofuna, Louie meets William Harris, a marine with a photographic memory. Harris is beaten to a pulp by the Quack and never quite recovers his memory. Harris is eventually transferred to Omori, and although he's on death's doorstep when he arrives, he manages to recover. He stays in the Marines and disappears in the 1950s in Korea.
There's also one-legged Fred Garrett, who was once put in the cell where Louie carved his name. Later on they end up in the same hospital in Honolulu after the war ends, and they reunite at a restaurant two years after this. Fred has a prosthetic leg and freaks out over a plate of rice, a moment of post-traumatic stress from his years in the Japanese POW camps with only rice to eat.
Finally, there's Frank Tinker, a dive-bomber pilot and opera singer (4.20.36). Louie and Tinker plot to escape Ofuna, but their plan never comes to fruition.
There are both good guards in the Japanese POW camps and bad ones. You can tell the bad ones by their nicknames—like the Quack, the Weasel, and, of course, Shithead. (That's Mr. Shithead to most of you.)
Also known as "The Butcher," the Quack is the most hated official in Ofuna. He tortures and mutilates captives (like William Harris, who we mentioned above) "while quizzing them on their pain" (4.19.35). When the men steal a map from the Quack, he beats Bill Harris until Bill is disfigured and cannot recognize his friends. After the war, the Quack is sentenced to hang.
Louie gives the Weasel a "coquettish" (4.22.7) eyebrow trim à la Marlene Dietrich, but somehow manages to escape retribution for the prank. And the guard known as Shithead violates Gaga the duck and kills him. These are not nice men, in case you couldn't guess.
Not all the Japanese Louie meets are bad, however. A guard known as Kawamura draws pictures of cars, planes, ice cream, and the like, writing the Japanese names for them to help the POWs learn to communicate. He even takes revenge on guards who hurt Louie. Hirose has captives fake screaming so it only seems like he beat them, and Kano once "snuck sick man from the sadistic Japanese doctor and into the hands of a POW who was a physician" (4.24.27). Yup—they're not all bad just because they're POW guards.
Even though Kano is relatively kind, he gets sentenced to jail for a time, being confused for Hiroaki Kono, a man described as a "roaring Hitlerian animal" (4.28.8). After Kano's release, he hesitates to contact his POW friends for fear of reminding them of terrible times.
These men prove that just because war causes people to do bad things, not all people succumb to the pressure to be evil. Perhaps it is only the ones who are already evil at heart.