Pacy Lin, a Taiwanese-American girl from New Hartford, New York, reluctantly travels with her family to Taiwan for a month-long trip to celebrate Grandma's 60th birthday. Pacy, her older sister Lissy (14), and her younger sister Ki-Ki (7) wear matching hot-pink overall dresses for the flight, which embarrasses all three. Pacy wishes they could visit her best friend Melody in California instead. Dad insists the girls need to know their "roots" and describes Taiwan as
bao dao, meaning "treasure island." Mom explains that Grandma's 60th birthday marks five complete cycles of the 12-year Chinese zodiac, which is considered very lucky.
On the airplane, Lissy points out that Pacy holds chopsticks incorrectly, and Pacy cannot manage the corrected grip. Mom announces she has enrolled the girls in a cultural program for Taiwanese-American kids: Lissy will take calligraphy, Pacy painting, and Ki-Ki paper cutting. The news triggers a painful memory. At a Taiwanese-American convention, other girls called Pacy a "Twinkie," meaning "yellow on the outside, but white on the inside," and mocked her for not speaking Chinese. She fears Taiwan will bring more humiliation.
In Taipei, the family is greeted by Auntie Jin and her husband, whom the girls nickname "Uncle Flower" because he gave them a bouquet of lilies. At a famous dumpling restaurant, Pacy discovers
xiaolongbao, soup dumplings with broth inside. Uncle Flower says eating them without making a mess marks you as a "real Chinese" person, but Pacy dribbles soup down her chin, feeling the dumpling can tell she is "just visiting." At an art store, Dad explains name chops, personal stone seals carved with one's identity. Each girl chooses a chop based on her zodiac birth year but must decide what to inscribe. On the walk home, a fortune-teller reads Pacy's palm and declares she has a special creative skill but will get into trouble. Mom explains each girl's Chinese name; Pacy's, Lin Pai-se, means "precious thought," though Pacy feels it does not fit her.
Pacy's first painting class fills her with anxiety. The room of entirely Asian students reminds her of the convention. The teacher explains that Chinese painting conveys ideas rather than realistic images and that marks cannot be erased. Pacy struggles with ink that spreads uncontrollably, and her art talent seems absent. Her desk neighbor, Audrey Chiang, is dismissive and competitive, looking at Pacy with pity when Pacy admits math is her worst subject. In later classes, Audrey publicly criticizes Pacy's work, and Pacy channels her anger into determination to beat her.
Lissy reveals she also dislikes her class and asks Pacy to accompany her to a glamour photo shoot, a late birthday gift from Grandma. At the studio, makeup artists apply fake eyelid folds that make Lissy's eyes look rounder, like their non-Asian classmates' eyes. Pacy remembers a classmate telling her she could not make a "cute couple" with a boy she liked because she was Chinese and did not "match" anyone. She feels caught between not being Asian enough in Taiwan and being seen as too Asian at home.
The family takes a bullet train to Taichung, where Cousin Clifford, Dad's relative who has lived in Taiwan for over two years, serves as their guide. At a market, a vendor angrily addresses Pacy in Chinese after she nearly steps into a display of eels. Pacy can only repeat "Meiguoren" (American), but the woman cannot understand why a Chinese-looking girl does not speak the language. Clifford rescues Pacy and explains that her parents chose not to teach their children Chinese so the family would fit in at home. The encounter leaves Pacy feeling hardened and angry, convinced that people in Taiwan either despise her or look through her "like a ghost." At a temple in Lugang, Clifford reflects on how difficult it was to live in Taiwan without reading Chinese, giving Pacy new perspective on her parents' immigrant experience.
Back in Taipei, the teacher, whose name Pacy finally learns is Li Mengshan, demonstrates a masterful painting. Pacy realizes she misjudged him because of his halting English, just as people in Taiwan misjudge her for not speaking Chinese. Because the girls' personal chops are not ready in time, the teacher offers generic word chops for students to use on their paintings. On the last day of class, Pacy creates her best work: three pink birds on a bamboo branch, representing herself, Lissy, and Ki-Ki, painted in the same hot pink as their airplane dresses. She stamps it with what she believes is the "happiness" chop.
The family visits Taipei 101, a famous bamboo-shaped skyscraper with an observatory. When Lissy's retouched glamour photos arrive, Pacy tells her sister she looks better in real life. On the subway, a pickpocket steals Mom's change purse, which contains only tissues. Mom's sadness at being seen as a tourist rather than a local helps Pacy understand that Mom is no longer "from" Taiwan; they are all "visiting ghosts."
At the night market, a sprawling, carnival-like open-air food market, Pacy becomes separated from her family and wanders through the crowds unable to ask for help, feeling invisible like a hungry ghost. The fortune-teller's prediction of trouble has come true. Cousin Shogun finds her, and she sobs uncontrollably. In the taxi home, Mom reveals that the family left Taiwan because of martial law, a period of oppressive military rule, and tells the story of Dad's older brother, Big Uncle, being arrested by military police when Dad was a boy. Pacy thinks about how Big Uncle still has a warm smile despite what he endured. Her family learned to live with their ghosts, and she resolves she can, too. Back at Grandma's apartment, surrounded by relatives sharing dumplings, Pacy feels safe and treasured, understanding at last that she is "a precious thought, after all."
At the art exhibit, Ki-Ki wins a blue ribbon for her paper cut. Pacy discovers her chop stamp says "forever," not "happiness," because someone mixed up the teacher's chops. Neither Pacy's painting nor Audrey's wins the class ribbon; it goes to Eva Wong, a friendly classmate. Pacy is disappointed but recognizes that winning is not the only source of happiness. She regrets spending the course competing with Audrey instead of making friends, connecting this to the teacher's lesson that marks in painting cannot be erased. Mom tells Pacy that being Taiwanese-American is permanent, like a brush stroke. Pacy asks to have her name chop carved in both Chinese and English, and feels a surge of relief at finding her identity.
For Grandma's birthday party, Pacy stamps her newly carved name chop, bearing both her Chinese characters and "GRACE PACY" in English, onto her painting and gives it to Grandma. She realizes the three birds sit on bamboo, a symbol of wishing, and that "forever" fits the painting perfectly after all. Lissy gives a poster from her photo shoot, and Ki-Ki presents a handmade award reading "#1 GRANDMA." A Chinese lion dance performed by Uncle Flower, Cousins Shogun and Julian, and their father highlights the celebration. Grandma gives each grandchild a red envelope containing 60 American dollars, one for each year of her life. A guest calls the girls "talented," and Pacy feels a burst of happiness, realizing that even as Americans who cannot speak Chinese, they are liked and loved in Taiwan.
On the airplane home, Pacy recalls Dad's words from the start of the trip: "You take something with you, you leave something behind, and you are forever changed." She opens a farewell gift from Uncle Flower: a warm container of dumplings with chopsticks taped to it. Everyone laughs. Mom asks if the trip was fun. Pacy says yes, and this time, Mom's idea of fun is exactly the same as hers.