The film centers on Sakiko Suzuki, a woman whose life has been shaped by a compulsive fixation on cash since childhood. She is obsessed with cash and would regale friends with stories about her savings, even pressuring would-be dates to hand over money upfront. After college, her family suggests she become a bank teller. She lands the job, but quickly grows disillusioned because she is counting other people's money. Then bank robbers kidnap her and stuff her in a trunk with a bright yellow suitcase filled with stolen cash. The thieves take a wrong turn in the woods and crash the car. She escapes with the briefcase but falls into a river and winds up in an underground pool, where she tries to drown by letting go of the suitcase. Instead, she is carried downstream and is granted medical leave by the bank.
The rest of the film traces her single-minded quest to retrieve the money. One Sunday, she convinces her family to go to the woods, but they quit when it starts raining. Her mother Tomiko Suzuki and her father Mikio Suzuki watch with concern as she ventures on alone. Undeterred, she pushes ahead, suffers an accident and winds up in the hospital again. This setback becomes a catalyst for a more careful plan: she moves out of the family home, returns to college to study geology, and starts intensive training in swimming, scuba diving, mountain climbing, and driving, while buying a mountain of surveying equipment. She racks up victories in swimming and mountain climbing, but she is not chasing fame; her goal remains money-driven. After a floor collapses under the heavy gear in her apartment and another hospital stay, she escapes, steals from her family, and even frames a research assistant for stealing a bag of money from the bank; she steals the man’s truck and heads to the woods to recover the suitcase. She formally apologizes to her family for the theft. On the radio, news about Bermuda Triangle treasures sparks a new plan to obtain a sailing license. The film closes with Sakiko returning to the woods to hide the yellow briefcase once more, a symbol of money’s pull and her relentless drive to control it.
