Abandoned at the age of five by her mother, deaf and mute Mahiru Morita's life has been filled with sorrow. Living with adoptive parents in Okinawa, she is also routinely treated cruelly at home and at school. But hope springs eternal as she dreams of one day finding her true mother living in far-off Tokyo. Can her dream come true? When young Kazuki, a young man attending university in Tokyo, comes to visit Okinawa on a scuba diving trip, a life-threatening incident brings the two young hearts together. As their adventure unfolds, young Kazuki recounts to Mahiru the fable of how a young girl is showered with coins from.

五岁时遭母亲遗弃，又聋又哑的森田真昼（星野真理饰）的生活充满悲情。与收养她的父母生活在冲绳岛。在学校和家里她时常受到虐待以及欺负。但她始终抱有一个梦想，那就是总有一天在遥远的东京找到自己的亲生母亲。她的梦想能否实现呢？
村冈一树（藤原龙也饰）是东京一所大学的四年级学生，学校潜水俱乐部的成员，为了参加俱乐部的夏令营来到这个小岛。偶然的一场事故把两颗年轻的心牵到了一起。那天，一树给真昼讲述了一个小女孩如何得到空中的星星落下来变成金币的故事。