University student Akira meets the lovely 14-year-old Yumi, whom he had tutored years ago. Her mother is told by her doctor that the schoolgirl has leukaemia and has only 6 months to live. So the mother entreats Akira to be her special friend. Yumi's condition remains stable for a while, but on the day that Akira leaves for Nagano for his teacher training, she suddently falls ill in school and then goes to a friend's villa in the resort town of Karuzawa to recuperate. She is able to visit Akira from time to time, and this eases her fear and suffering. But when summer is over, Yumi's condition deteriorates, and finally Akira takes her to Mount Hodaka where, as she falls into her final delirium, they express their deep love for each other.