In this deeply moving first-person story, an introverted high school boy finds his classmate's diary—and learns her biggest secret. Yamauchi Sakura is dying from a pancreatic disease and now he is the only one person outside her family to know the truth. The last thing the boy wants is to be her friend, but Sakura's cheerful demeanor and their shared secret draw them together in this heartrending tale of friendship and mortality.