Based on the true story and book about it.

In October, high school student Kazunori Kitahara was attending a table tennis match, but after being examined for chronic discomfort in his left leg gets the shocking diagnosis of Ewing's sarcoma (a type of cancer). While being supported by his family, he decides to fight the disease and begins his life in the hospital. Although it was going well for a few months after the first anticancer drug treatment, the growth of cancer cells was rapid, and at the recommendation of his doctor Agawa, Kazunori switched to radiation therapy.

When Kazunori heard from his best friend Takumi Makiuchi about taking the medical school entrance exam, he suddenly told his family that he had decided to take the University of Tokyo entrance exam. Despite his condition continuing to get worse, he is able to graduate high school and pass the entrance examination. However, shortly after Kazunori attended his first lecture at university in April, he was admitted to the hospital again after his cancer had metastasized. He celebrates his 19th birthday in late July and travels to heaven the next day after eating a small amount of his mother's homemade food on a hospital bed.