The i of the title represents both the imaginary unit in math (i2 = −1) and the English first-person pronoun I. It is also a homophone for ai, the Japanese word for “love,” as well as for Ai, the name of the main character. When her high school math teacher declares during a lesson on imaginary numbers that “i does not exist in this world,” Ai Soda Wild feels as if her own existence has been denied. The line lodges deep in her consciousness and continues to haunt her for some time to come.
Ai was adopted from Syria by her American father and Japanese mother. Her early childhood years were spent in the upscale New York neighborhood where her parents lived, but the family moved to Tokyo when she was in middle school. She has fretted about the fact that she is adopted from a very young age. Why had she been the one her loving parents chose? Who among the untold numbers of other unfortunate children had she displaced? The comfortable circumstances in which she lives bring her pangs of guilt, and news reports from around the world about civil wars, terrorism, and natural disasters make her feel as if she alone has been wrongly spared. As a bystander, she feels she has even lost the right to mourn the many tragedies she hears of. Ultimately, she begins keeping track of the death tolls from those various calamities in a notebook. Countering these tendencies toward self-abnegation is the realization that the voice in her head repeating “i [Ai] does not exist in this world” disappears when she is with her best friend Mina, a girl she met after starting high school.
When Japan’s northeastern Pacific coast suffers an earthquake, tsunami, and nuclear plant meltdown, the introverted Ai begins to come out of her shell. Rebelling against her parents, who are in America at the time, she decides to remain in Japan. At a demonstration to protest nuclear power she meets a photographer named Yū, and they subsequently get married. Lacking a sense of her own roots, Ai wants to establish a family tree for herself by having a child. But after going through infertility treatments, she miscarries. At that very juncture Mina reveals that she is thinking of getting an abortion, and the two young women have a falling out. Ai feels at a loss, but nudged by Yū’s remark that “You can still love someone even if you can’t understand their point of view,” she decides to visit Mina in Los Angeles. The two longtime friends talk through the night—about the ravages of war in Syria, about the state of the world, about the future—unburdening their hearts to each other. Ai realizes that even when she’s not directly involved in tragic events around the globe, it’s important to be able to imagine how they affect those who are. In the water at the beach the next day, she raises her voice in self-affirmation: “Ai does exist in this world.”
In the present day, with information pouring in constantly from every corner of the globe, the world’s tragedies thrust themselves upon us day in and day out. It is difficult for anyone to escape a frustrating sense of powerlessness in the face of it all. This story follows the trajectory of a young woman whose unusual background makes her especially sensitive to these conditions as she comes of age and finds herself.