The nameless brides
One obvious symbolism in the book is that the women in the story have no name. That is a clear symbol for the unanimous (and therefore systematic) nature of their struggle, and it also symbolizes their feelings of meaninglessness and lack of identity. Their transfer from Japan to America has made them into more of an object than a person in terms of their public treatment. Back in Japan, they had names and lives and friends and family, but in America, they are just "Japanese foreigners." The symbolism of their being brides is confused by their disappointing spouses. They feel more like property every day, unfortunately.
The absurd stranger
The women share a point of view that is discovered by motif. The motif in question is the absurd stranger, like Camus's famous conception of it. They belong to a world whose culture is unknown, and therefore, the assumption which governs the American point of view that their way of life automatically explains itself is not there for the immigrants. They are trapped in a world of absurdity, never knowing what to expect or what to do. They struggle to communicate with people, and securing approval and building community are extremely difficult.
Pearl Harbor and disenfranchisement
Pearl Harbor is an inciting incident in the plot. While before life was unpleasant and uncomfortable, Pearl Harbor incites a new experience among the Japanese women. Now they have gone from disapproved of to literally unsafe. The racism of their communities makes for a constant threat on their well-being, and the internment in government camps is a literal symbol of hopelessness. The government is breaking its own rules, getting away with it, and none of the citizens seem to care; it is an astonishingly uncanny symbol for human disenfranchisement caused by racial prejudice. In a nation with a history like the United States's, those internment camps must have been quite horrifying, because the girls never know what the government is truly capable of.
The missing neighbor
The government is not the origin of the dysfunction in this novel, and the reader sees that through symbolic conversation. The reader encounters neighborhood early in the book as the Japanese women compare and contrast American community with Japanese community. American community is highly anonymous, whereas Japanese people are very knowledgable about their neighbors. When the Japanese community randomly vanishes from Californian neighborhoods, the neighbors symbolically comment on their concern for others—they notice, but they assume everything is alright.
J-town
In immigrant fiction, there is a frequent motif of highly dense ethnic populations and their rejection of foreigners. The Japanese communities that existed in California largely reject the Japanese girls because they are concerned with preserving a tradition that is somewhat exclusive. The communities have a strict border to protect the culture from the surrounding influence of Californian life, but the girls have an ethical challenge facing them about adjusting and adapting for their own sakes, so they are often not able to sustain themselves under such a conservative model. When they are rejected by other Japanese people, their isolation is truly evident.
