2004年，34岁的松本朔太郎（绪形直人 饰）收到高中老师寄来的明信片，将他封闭且逃避了17年的记忆带回到17岁的那个夏天。1987年。高中时代的朔太郎（山田孝之 饰）和广濑亚纪（绫濑遥 饰）的恋爱非常甜蜜，对两人来说快乐的瞬间感觉就像永远一样。自从亚纪得了不治之症后，两人的命运发生了急转弯。虽然亚纪在努力对抗病魔，但现实毕竟是残酷的，在朔要带亚纪去澳大利亚乌鲁鲁的时候，亚纪却在机场晕倒了。虽然这是无法改变的事实，但失去亚纪让朔太郎对于人生、爱情产生了永久的失落感。 “我17岁时，在没有她的世界。”17年后，朔太郎是否能找到那把走出迷宫的钥匙？可以亲手送走了一直弥留在自己心中的亚纪吗？"I thought I might be using a lifetime's happiness in a moment. I was that happy and she was that beautiful." A young boy stands on the red earth of Australia under its blue sky. It is 17-year-old Sakutaro Matsumoto. His time with the girl comes back to him. The colored sand runs through his hands and a tear appears on his cheek. He wakes up. It's 2004 and he is 34years old and in Japan. He thinks "I have been in a world without her for 17 years." Returning home to see his old high school for the last time before it is demolished, Saku confronts anew the loss of the love of his life, Aki, to leukemia 17 years ago. Now a medical researcher at graduate school, he has been living as if half of him died with her since then. Based on the bestselling novel that sold over 3 million copies, the past and present come together in this love story that is both pure and sad.
