69 (シクスティナイン , Shikusutinain ) is a roman à clef novel by Ryu Murakami. It was published first in 1987. It takes place in 1969, and tells the story of some high school students coming of age in an obscure Japanese city who try to mimic the counter-culture movements taking place in Tokyo and other parts of the world.
The title 69 refers to the year that the story takes place.
The text doesn't state that the title 69 refers to the story's setting in 1969; I can see why the algorithm assumed it due to the number match, but the title could have another meaning.