Netsuzou: Chijin no Ai

Tanizaki's novel tells the story of an ordinary salaryman named Joji Kawai, who meets a 15-year-old beautiful waitress at a cafe named Naomi. Joji makes an agreement with Naomi to live together "like friends," and gives her education and lessons of manners befitting a wife. However, Naomi turns into a woman Joji never expected.

(Source: Anime News Network)