When Isabelle Nieto moves to Mazatlán to take over her late sister Lorena's tuna fishery, she finds Lorena's autistic daughter Karen, who has been living as a feral child. Isabelle takes Karen in to raise and educate her. As she grows older, Karen develops a love of diving, and uses her understanding of animals to create plans to make Consolation Tuna more humane.
Me, Who Dove into the Heart of the World contains examples of:
- Better with Non-Human Company: Karen finds people in general confusing and unpleasant. However, her understanding of the wants and needs of tuna allow her to become the first person to successfully breed bluefin tuna in captivity.
- Cannot Tell a Lie: Karen is incapable of either lying or fantasizing. She considers this an advantage because she's more connected to reality and her senses than most people.
- Don't Make Me Take My Belt Off!: Karen has scars from Lorena beating her with a belt buckle.
- Dramatic Sit-Down: Karen's business partner, Earnest Gould, calls her and tells her to sit down before he tells her that their tuna canneries have all been blown up.
- Eco-Terrorist: Karen is kidnapped by four members of the Animal Rights Militia, who hate her because True Blue Tuna's cruelty-free tuna sells for so much that it's increased the price of all bluefin tuna, which worsens the overfishing problem. The terrorists threaten to blow up her plane if she doesn't shut down all her fisheries in six months, then release her. Karen reports the kidnapping to Interpol, who fail to find the kidnappers, but assure her that although ARM has no qualms about destruction of property or psychological torture, they draw the line at physical violence. A few years later, the same people blow up all seven of True Blue Tuna's fisheries. Karen is actually grateful, because she was already planning to shut down the fisheries and turn her artificial tuna breeding grounds into a tuna preserve.
- Family Eye Resemblance: Lorena's staff don't even know Karen is her daughter. They think she's just a stray Lorena allowed to live on the property. Isabelle becomes convinced that Karen is her niece when she sees that she and Karen have the same light green eyes.
- Handshake Refusal: For most of her life, Karen refuses to shake hands because she hates the feel of bare skin. When she does shake a man's hand, she immediately runs to the bathroom to vomit. Eventually she learns that if she counts a person's finger bones with her thumb, she can tolerate the feeling for several seconds.
- Horrible Housing: The mansion where Lorena and Karen lived was practically a ruin, with the roof falling in, missing windows, and an ant infestation. After Isabelle moves in, she has the place repaired.
- Idiot Savant: Tests have found Karen's intellectual abilities in most areas range from kindergarten to second-grade level, but she has savant skills in memory, spatial awareness, and concentration.
- Inkblot Test: At college, Karen is brought into a Quantitative Psychology class so the students can study her. At one point the professor gives her an inkblot test. She describes what she sees: inkblot, bigger inkblot, two inkblots, several inkblots.
- Interrupted Suicide: After the death of Isabelle, Karen decided to commit suicide by diving to the bottom of the ocean and waiting for her oxygen tank to run out. She passes out, then suddenly wakes up, her tank almost empty. She wants to live now, but doesn't have the strength to swim to the surface. Then she sees a beautiful angel swimming towards her, and when she touches it, her whole body feels electrified. The angel takes her hand and lifts her to safety. As she rises, she realizes what actually happened: she was shocked by a jellyfish, which her hypoxic brain saw as an angel, and which is now trying to flee from her as she holds onto it. She lets the jellyfish go and swims to the surface with the last of her strength.
- I Should Write a Book About This: The book ends with 41-year-old Karen writing her autobiography.
- Married to the Job: Gould spent so much time working that he barely got to know his wife, sons, or grandchildren. After he retired at age 63, he decided to spend his free time with his family, only to quickly find that he couldn't stand any of them. His sons told him that the reason they were both so unpleasant was because they had been traumatized by his absence, and his wife told him she'd been having an affair for a decade that he'd never cared to find out about. Gould left his family, and came out of retirement not long after.
- Messy Hair: Karen's hair is so matted that Isabelle and the servant Gorda have to shave off most of it.
- Never Learned to Talk: At age nine, Karen communicates only in grunts. Isabelle takes her in and teaches her to speak, starting with the pronouns "Me" and "You." Karen learns to read at the same time she learns to talk, so Isabelle sticks labels on everything in the house and has the staff wear tags showing their job titles. Soon Karen talks nonstop, gleefully reciting lists of nouns and things she heard on the radio.
- Never Suicide: Japan's minister of agriculture, livestock, and fisheries commits suicide by hanging himself from the living room door of his apartment. Karen becomes convinced he couldn't have done it - suicide is seen as honorable, but being seen in your pajamas and being strangled with a dog leash are not honorable, and it's impossible to hang yourself from a door without going through the time-consuming process of nailing the leash to something. Karen doesn't think much about it for the next few years, until the same group of eco-terrorists threatens to kill her if she doesn't stop killing tuna, and later blows up all seven of her fisheries.
- Private Tutor: After Karen attends a special school for a few years, Isabelle pulls her out, hires a private tutor in the afternoons to teach her only what she's interested, and takes her to the cannery in the mornings.
- Produce Pelting: Protestors from Clean Seas shout "Killer!" at Karen. One of them throws a tomato, which hits her in the eye.
- Verbal Tic: Karen often repeats words and phrases when she talks, especially when she's uncomfortable.
- Wild Child: After Karen was found to be mentally disabled, Lorena completely ignored her when she wasn't abusing her. When Isabelle finds her, she's naked, severely underweight, and caked in mud.
