One day on her way to school, middle school student Aya (Asae Onishi) suddenly falls to the ground. The doctor diagnoses her with spinocerebellar degeneration, a rare and incurable neurological disease. Entering high school, Aya's condition continues to worsen as physical movements become more difficult. Forced to attend a special boarding school, she nonetheless finds hope and happiness through the support of her new friends and family. Working hard, she completes her high school education and bravely begins a new stage in her life, despite her weak health and continuous trips to the hospital. Aya never gives up, living each day of her life to the fullest until the very end.
This beautifully moving drama is based on the real-life struggles of a 15-year-old girl named Aya who suffered from an incurable disease, but lived life to the fullest until her death at 25. The script is based on the diary Aya kept writing until she could no longer hold a pen. The book that later followed entitled “One Litre of Tears" has sold over 1.1 million copies in Japan alone. Fifteen year old Ikeuchi Aya was just a normal girl, soon to be high school student and daughter of a family who works at a shop that makes tofu. As time passed, unusual things started happening to Aya lately. She started falling down often and walks in a strange way. Her mother Shioka, takes Aya to see the doctor, and he informs Shioka that Aya has spinocerebellar degeneration - a terrible disease where the cerebellum of the brain gradually deteriorates to the point where the victim cannot walk, speak, write, or eat. A cruel disease, as it does not affect the mind in the least. How will Aya react when told about her disease? And how will Aya live from now on?