The Irony of Akiko's Older Sister
Older siblings usually feel an instinct to look out for and protect their younger siblings. In Akiko's case, however, her older sister sold her into slavery the moment their parents died. She wanted the money for her dowry in order to provide for her own safety during troubling times.
The Irony of the "Comfort Women"
The Japanese named their war prostitutes "Comfort Women." Such naming is a sick joke because these women have no comfort at all -- to give or to receive. They're used like objects instead of treated like people. The euphemism seems wildly inappropriate, but it's difficult to expect otherwise from such an atrocious institution as sex slaves.
The Irony of Beccah's Birth
Akiko's first child is forcibly aborted during her time in the camp. She never recovers from the procedure either physically or emotionally. When she finds out that she's pregnant the second time in Hawaii, she nearly laughs at the irony. Now she no longer has any sense of personal identity or meaning to her life, believing her soul died in the camp. She wishes she had been allowed to keep the first child back when she was still a person who could mother it well.
The Irony of Spiritualism
Spiritualism, along with most spiritual and religious practices, tends to make people uncomfortable. This is why all the kids at Beccah's school ridicule her mom for calling on the spirits. For Akiko, however, her spiritual practices provide her with a sense of peace amidst the traumatic memories floating around in her mind.
The Irony of Bradley's Death
When Akiko tells Beccah that she wished for her husband's death making it happen, she scares the girl. Beccah remembers all the times she had been angry with her mom and wished she would die. She's worried that she is somehow responsible for her mom's death now because of those moments of anger. It's a coincidence that Beccah's situation with her mom so closely parallels how Akiko dealt with her husband's abuse.
