A medical team is dispatched to the patients on a helicopter to provide medical care in the field as soon as possible. One day, four young physicians are assigned to this latest medical system. The doctors experience traumatic medical situations, deal with personal ambitions, witness the fragility of life, and they grow personally and professionally.

Yuri Kashiwaga was once known as a genius pianist. One day, she returns to her hometown in Goto Islands from Tokyo. There, she begins to work as a temporary teacher at a middle school and advisor for the school chorus. The chorus aims to take part at a competition. Yuri gives the members of the chorus members an assignment. She instructs them to write a letter with the title of "To myself 15 years later." The 15-year-old boys and girls write about their secrets and worries.