Ironic obligation
The theme of obligation in the narrative is a weird one, because it is ironically antithetical to Ichiro's character. It is as if to say Ichiro is plagued and tormented by obligation, when all he wants is to be free. He endures two years in a US prison camp, when he had done nothing wrong, and then, he gets a letter in the mail. He's been drafted—obligated to the same government that imprisoned him. Then when he doesn't go, they issue a warrant, obligating him to jail time—two years when all is said in done, in federal prison, by the way. When he gets out, his community tells him about all the responsibilities he has now, and how he isn't living up to their standards. Obligated again.
The internment irony
The irony of internment is clearly that in light of American law, the Japanese internment must be considered among the most heinous moments of injustice in American history, because the people in the government allowed paranoia and racism to determine policy, instead of honoring the rights of the Japanese, some of whom had—many of them—no real connection to Japan anymore. It's plain old xenophobia at the highest level of command.
Ironic Emi
Emi's character is ironically available and unavailable. She symbolizes Ichiro's tender approach to relationship, because he is paranoid, and because Emi is patient. She has been somewhat abandoned by a husband who, when allowed to go back home to Emi, choose to stay. So, she doesn't know if she'll ever see him again, but that's great news for Ichiro who gets time to be with her and talk to her.
The irony of loyalty
The irony of loyalty in the novel is portrayed in the relationship between Ichiro and his community, and it is also portrayed in the relationship between that Japanese community and their various political opinions, because many of them challenge him for not being loyal enough to his home, America, that is, to go fight for it, but Ichiro feels other kinds of loyalty as well, like the loyalty to look out for himself, especially when that same government just had his entire family in internment camps.
The irony of citizen enemies
This novel explores the government's merciless and ironic decision to categorize entire populations as enemies of the state who were already citizens of the nation, based on nothing except race and ethnicity. The decision to round up Japanese Americans is hauntingly similar to the Nazi treatment of Jews, proving that ironically, it wasn't just Nazis with racist agendas.
