凭借考察东京风物的机缘，年事渐高的作家深野纯一（石橋蓮司 饰）结识了26岁的美丽女孩小川加奈（大竹一重 饰）。这个和年轻时的情人有着相似面容的女子，令深野那颗开始衰老的心为之所动。在此之后，他们的交往逐渐加深，加奈来到深野的家中兼职整理书房。虽然深野的老母亲提出警告，但是他对加奈的牵挂愈来愈深。在一次旅行途中，这对有着悬殊年龄的男女终于不可遏止地结合在一起，二人更决定结为夫妇。与此同时，莫名的电话却让深野心生忧虑。他开始有意识地探寻妻子的身世之谜，浪漫爱情背后的阴谋渐渐浮出水面……

本片根据小林信彦的原作改编。

Fukano, an elderly novelist who grew up in the mountains of Tokyo, met a young woman, Kana, for the first time in Fukagawa. Overcoming the age difference, they are strongly attracted to each other. However, in Fukano, in addition to the problem of downtown and uptown, there was a deep “river” that separated women and men. However, Kana, on the other hand, easily crossed that "river" due to her sexual love with Fukano. "I never thought I'd live west of the Sumida River," Kana said. However, behind this lies the conspiracy of Fukano's old lover, Junko. The two get married, but Kana's behavior is gradually haunted by a mystery, and the shadow of her detective and old man flickers. The core of the mystery involved a strange sex shop