As a result of a car accident, the Ph.D. who is obsessed with mathematics (Satoshi Terao) suffers from strange amnesia. From then on, he could only keep 80 minutes of memory, and after 80 minutes, everything was like a new beginning, so he must always put a note on his body to remind himself of something important. At that time, the doctor went to study in England with the financial support of his elder brother. Since his brother's death, his sister-in-law (Liulizi Asahi) took over the hard-working management of the family's textile mill, but the family still inevitably fell. Due to lack of time for his care, my sister-in-law invited the housekeeper Xingzi (Akira Shenjin) to take care of the doctor. Xingzi brought his son Agen to the doctor, who took care of everything in the doctor's life with great patience and tolerance. And the doctor also wants to show the beautiful scene of the mathematical kingdom to the mother and son. The film is based on the novel of the same name by Akutagawa Award winner Yoko Ogawa and won the Best Movie score of the Daily Film Award in 2007.