毕业在即的大学生美千留(榊林乃爱 饰),在冬日的一天收到了意外来信,写信人竟是从未谋面的同父异母妹妹。在美千留很小的时候,父亲便离开了她。此去经年,关于父亲的记忆早已稀薄,但籍着这封信的到来,父亲的身影似乎在美千留的心中日益清晰。在这个从学生向社会人转化的重要时刻,美千留和许许多多的同龄人一起经历着自内而外的蜕变……This is a story of a young woman and her coming of age in Japan. In the winter before her college graduation, Michiru received a letter from a girl. Apparently, they are sisters who shared the same father. The letter explained their father who has left Michiru from her birth. Even though she had never cared about him, the fact about his existence spread within her. As she explored about him, she experiences irresistible youth and separations in her life. The youth of a girl is 'like the music pouring out from the world,' and fragile like a raindrop.(C)Tokyo New Cinema