最后一封信

岸边野裕里（松隆子）在姐姐远野未笑的葬礼上，遇到了姐姐的女儿远野鮎美（广濑铃）。无法接受母亲亡故的鮎美，也无法打开母亲留下的最后一封信。裕里参加了要和大家报告姐姐往生的同学会，巧的是，她的初恋对象镜史郎（福山雅治）也来了，两人在一封封书信的联系中串接起三人当年的故事。It is only at their sister's and mother's funeral when a woman meets her niece after many years. The niece is now a grown girl. The sister takes on the task of informing the deceased's friends of the death while the daughter cannot bring herself to symbolically accept the demise of her mother. In the midst of all this an old flame messages the sister to say he is still in love with her, but is he messaging the living sister or the dead one?